tag:blogger.com,1999:blog-28684040813847421612014-10-02T21:52:50.404-07:00IIT JEE Physics Practice SetsKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.comBlogger103125tag:blogger.com,1999:blog-2868404081384742161.post-23158560271119577992009-10-12T18:24:00.000-07:002009-10-12T18:32:42.389-07:00IIT JEE Physics Final Revision Set 49An inductor of inductance 2.0 mH is connected across a charged capacitor of capacitance 5.0 µF and the resulting LC circuit is set oscillating at its natural frequency. Let Q denote the instantaneous charge on the capacitor and I the current in the circuit. It is found that the maximum value of Q is 200 µC. <br />1. When Q = 100 µC, what is the value of |dI/dt|? <br />2. When Q = 200 µC, what is the value of I? <br />3. Find the maximum value of I. <br />4 When I is equal to one-half its maximum value, what is the value of |Q|? <br /><br />Nuclei of a radioactive element A are being produced at a constant rate α. The element has a decay constant λ. At time t = 0, there are N<sub>0</sub> nuclei of the element. <br /><br />5. Calculate the number N of nuclei of A at time t. <br />6. If α = 2N<sub>0</sub>λ, calculate the number of nuclei of A after one half life of A, and also the limiting value of N as t → ∞. <br /><br /><br />Source 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com44tag:blogger.com,1999:blog-2868404081384742161.post-48732782839783866982009-10-12T18:17:00.000-07:002009-10-12T18:24:28.673-07:00IIT JEE Physics Final Revision Set 48A conducting sphere S1 of radius r is attached to an insulating handle. Another conducting sphere S2 of radius R is mounted on an insulating stand S2 is initially uncharged. <br />S1 is given a charge Q brought into contact with S2 and removed. This procedure is repeated n times. <br /><br />1. Find the electrostatic energy of S2after n such contacts with S1. <br />2. What is the limiting valve of this energy as n →∞ ? <br /><br />3. A particle of mass m and charge q is moving in a region where uniform constant electric and magnetic fields <strong>E</strong> and <strong>B</strong> are present. <strong>E</strong> and <strong>B</strong> are parallel to each other. At time t = 0, the velocity <strong>v0</strong> of the particle is perpendicular to <strong>E</strong> (Assume that its speed is always << c, the speed of light in vacuum). Find the velocity <strong>v</strong> of the particle at time t. [You must express your answer in terms of t, q, m, the vectors <strong>v0</strong>, <strong>E</strong> an <strong>B</strong> and their magnitudes v0, E and B.<br /><br />Suorce 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-82008675715980612552009-10-12T18:11:00.000-07:002009-10-12T18:17:51.384-07:00IIT JEE Physics Final Revision Set 47The air column in a pipe closed at one end is made to vibrate in its second overtone by tuning fork of frequency 440Hz The speed of sound in air is 330 m/s. End corrections may be neglected. Let P0 denote the mean pressure at any point in the pipe, and ΔP0 the maximum amplitude of pressure variation. <br /><br />1. Find the length L of the air column. <br />2. What is the amplitude of pressure variation at the middle of the column? <br />3. What are the maximum and minimum pressures at the open end of the pipe? <br />4. What are the maximum and minimum pressures at the closed end of the pipe? <br /><br />5. A solid body X of heat capacity C is kept in a an atmosphere whose temperature is T<sub>A</sub> = 300 K. At time t = 0, the temperature of X is T<sub>0</sub> = 400 K. It cools according to Newton’s law of cooling. At time t<sub>1</sub> its temperature is found to be 350 K. <br /> At this time (t1) the body X is connected to a large body Y at atmospheric temperature T<sub>A</sub> through a conducting rod of length L, cross-sectional area A and thermal conductivity K. The heat capacity of Y is so large that any variation in its temperature may be neglected. The cross-sectional area A of the connecting rod is small compared to the surface area of X. Find the temperature of X at time t = 3t<sub>1</sub>. <br /><br /><br />Source: 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-22488540859529416292009-10-12T18:02:00.000-07:002009-10-12T18:11:31.648-07:00IIT JEE Physics Final Revision Set 461. The work function of a substance is 4.0 eV. The longest wavelength of light that can cause photoelectron emission from this substance is approximately: <br />(A) 540 nm (B) 400 nm <br />(C) 310 nm (D) 220 nm<br /><br /><br />2. X-rays are produced in an X-ray tube operating at a given accelerating voltage. The wavelength of the continuous X-rays has values from : <br />(A) 0 to ∞ <br />(B) λmin to ∞ where λmin > 0 <br />(C) 0 to λmax where λmax < ∞ <br />(D)λmin to λmax where 0 < λmin < λmax < ∞<br /><br />3. A particle of mass m is executing oscillations about the origin on the x-axis. Its potential energy is U(x) = k |x|³ where k is a positive constant. If the amplitude of oscillation is a, then its time period T is : <br /><br />(A) proportional to 1/√a <br />(B) proportional of a <br />(C) proportional to √a <br />(D) proportional to a³<br /><br /><br />Paragraph for 4 and 5<br /><br />A particle of mass 10<sup>-2</sup> Kg is moving along the positive x-axis under the influence of a force F(x) = – (k/2x²) where k = 10<sup>-2</sup> Nm². At time t = 0 it is at x = 1.0 m and its velocity is v = 0:<br /><br />4. Find its velocity when it reaches x = 0.5 m <br />5. Find the time at which it reaches x = 0.25 m <br /><br /><br />Source 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-5189968372581143292009-10-12T09:11:00.000-07:002009-10-12T09:27:14.111-07:00IIT JEE Physics Final Revision Set 45Questions may have more than one correct answer<br /><br />1. A non-conducting slid sphere of radius R is uniformly charged. The magnitude of the electric field due to the sphere at a distance r from its centre : <br />(A) increases as r increases for r < R <br />(B) decreases as r increases for 0 < r < ∞<br />(C) decreases as r increases for R < r < ∞ <br />(D) is discontinuous at r = R <br /><br />2. A transverse sinusoidal wave of amplitude a, wavelength l and frequency f is travelling on a stretched string. The maximum speed of any point on the string is v/10, where v is the speed of propagation of the wave. If a = 10^–3 m and v = 10 m/s, then λ and f are given by : <br />(A) λ = 2π × 10^–2 m,f = 10³ Hz/2π (B)λ = 10^–3 m, f = 10³ Hz/2π <br />(C) λ = 2π × 10^–2 m, f = 10<sup>4</sup> Hz (D)λ = 10^–3 m, f = 10<sup>4</sup> Hz<br /><br />3. A black body is at a temperature of 2880 K. The energy of radiation emitted by this object with wavelength between 499 nm and 500 nm is U1, between 999 nm and 1000 nm is U2 and between 1499 nm and 1500 nm is U3. The Wein constant, b = 2.88 × 10^6 nm–K. Then : <br />(A) U1 = 0 (B) U3= 0 <br />(C) U1 > U2 (D) U2 > U1 <br /><br />4. The SI unit of the inductance, the henry can be written as: <br />(A) Weber/ampere (B) Volt-second/ampere <br />(C) Joule/(ampere)² (D) ohm-second<br /><br />5. Two very long straight parallel wires carry steady currents I and –I respectively. The distance between the wires is d. At a certain instant of time, a point charge q is at a point equidistant from the two wires in the plane of the wires. Its instantaneous velocity <strong>v</strong> is perpendicular to this plane. The magnitude of the force due to the magnetic field acting on the charge at this instant is : <br /><br />(A) (μ° Iqv) / 2πd (B) (μ° Iqv) / πd <br />(C) (2μ° Iqv) / πd (D) 0 <br /><br /><br />1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-14180067824679447202009-10-12T09:06:00.000-07:002009-10-12T09:11:25.921-07:00IIT JEE Physics Final Revision Set 441. A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth. <br />(A) The acceleration of S is always directed towards the centre of the earth. <br />(B) The angular momentum of S about the centre of the earth changes in direction, but its magnitude remain constant <br />(C) the total mechanical energy of S varies periodically with time <br />(D) The linear momentum of S remains constant in magnitude <br /><br /><br />2. The torque <strong>r</strong> on a body about a given point is found to be equal to <strong>A</strong> × <strong>L</strong> where <strong>A</strong> is a constant vector and <strong>L</strong> is the angular momentum of the body about that point. From this it follows that: <br />(A) (<strong>dL</strong>)/dt is perpendicular to <strong>L</strong> at all instants of time. <br />(B) the component of <strong>L</strong> in the direction of <strong>A</strong> does not change with time. <br />(C) the magnitude of <strong>L</strong> does not change with time. <br />(D) <strong>L</strong> does not change with time. <br /><br />3. In a p-n junction diode not connected to any circuit : <br />(A) the potential is the same everywhere <br />(B) the p-type side is at a higher potential than the n-type side <br />(C) there is an electric field at the junction directed from the n-side to the p-type side. <br />(D) there is an electric field at the junction directed from the p-type side to the n-type side.<br /><br /><br />4. During the melting of a slab of ice at 273K at atmospheric pressure : <br />(A) positive work is done by the ice-water system on the atmosphere. <br />(B) positive work is done on the ice-water system by the atmosphere. <br />(C) the internal energy of the ice-water system increases. <br />(D) the internal energy of the ice-water system decreases. <br /><br />5. A spherical surface of radius of curvature R, separates air) refractive index 1.0) from glass (refractive index 1.5). The centre of curvature is in the glass. A point object P placed in air is found to have a real image Q in the glass. The line PQ cuts the surface at a point O and PO = OQ. The distance PO is equal to : <br />(A) 5R (B) 3R <br />(C) 2R (D) 1.5R <br /><br />Source: 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-45895332969792889552009-10-12T08:46:00.000-07:002009-10-12T09:05:47.211-07:00IIT JEE Physics Final Revision Set 431. A charge + q is fixed at each of the points x = x0, x = 3x0, x = 5x0 ….∞ on the x-axis and a charge – q is fixed at each of the points x = 2x0, x = 4x0, x = 6x0 …. ∞. Here x0 is a positive constant. Take the electric potential at a point due to a charge Q at a distance r from it to be Q/4πε<sub>0</sub>r. <br /><br />Then the potential at the origin due to the above system of charges is : <br /><br />(A) 0 (B) q / (8πε<sub>0</sub>x0 (ln 2)) <br />(C) (q (ln 2))/(4πε<sub>0</sub>x0) (D) ∞<br /><br />2. Let I be the moment of inertia of a uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle θ with AB. The moment of inertia of the plate about the axis CD is then equal to : <br /><br />(A) I (B) I sin²θ.. <br />(C) I cos²θ (D) I cos²(θ/2) <br /><br />3. A metal rod moves at a constant velocity in a direction perpendicular to its length. A constant uniform magnetic field exists in space in a direction perpendicular to the rod as well as its velocity. Select the correct statement (s) from the following : <br />(A) the entire rod is at the same electric potential <br />(B) there is an electric field in the rod <br />(C) the electric potential is highest at the centre of the rod and decreases towards its ends. <br />(D) the electric potential is lowest at the centre of the rod and increases towards its ends. <br /><br />4. A positively charged thin metal ring of radius R is fixed in the xy plane with its centre at the origin O. A negatively charged particle P is released from rest at the point (0, 0, z0) where z0 < 0. Then the motion of P is : <br />(A) period for all values of z0 satisfying 0 < z0 < ∞ <br />(B) simple harmonic for all values of z0 satisfying 0 < z0 < R <br />(C) approximately simple harmonic provided z0 < < R <br />(D) such that P crosses 0 and continues to move along the negative z-axis towards z = – ∞. <br /><br />5. A concave mirror is placed on a horizontal table with its axis directed vertically upwards. Let 0 be the pole of the mirror and C its centre of curvature. A point object is placed at C. It has a real image, also located at C. If the mirror is now filled with water, the image will be: <br />(A) real and will remain at C <br />(B) real and located at a point between C and ∞<br />(C) virtual and located at a point between C and 0 <br />(D) real and located at a point between C and 0 <br /><br />Source: 1998 JEE paperKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-42416537881844947022009-10-12T04:38:00.000-07:002009-10-12T04:42:20.161-07:00IIT JEE Physics Final Revision Set 421. The half life of <sup>131</sup>I is 8 days. Given a sample of <sup>131</sup>I at time t = 0, we can assert that: <br />(A) no nucleus will decay before t = 4 days <br />(B) no nucleus will decay before t = 8 days <br />(C) all nuclei will decay before t = 16 days <br />(D) a given nucleus may decay at any time after t = 0 <br /><br />2. Two identical containers A and B with frictionless pistons contain the same ideal gas at the same temperature and the same volume V. The mass of the gas in A is mA and that in B is mB. The gas in each cylinder is now allowed to expand isothermally to the same final volume 2V. The changes in the pressure in A and B are found to be DP and 1.5 DP respectively. Then : <br />(A) 4 mA = 9mB (B) 2mA = 3mB<br />(C) 3mA = 2mB (D) 9mA= 4mB <br /><br />3. A given quantity of an ideal gas is at pressure P and absolute temperature T. The isothermal bulk modulus of the gas is: <br />(A) 2/3 P (B) P <br />(C) 3/2 P (D) 2P<br /><br />4. Two cylinders A and B fitted with pistons contain equal amounts of an ideal diatomic gas at 300K. The piston of A is free to move, while that of B is held fixed. The same amount of heat is given to the gas in each cylinder. If the rise in temperature of the gas in A is 30 K, then the rise in temperature of the gas in B is: <br />(A) 30 K (B) 18K <br />(C) 50 K (D) 42 K <br /><br /><br />5. A concave mirror is placed on a horizontal table with its axis directed vertically upwards. Let 0 be the pole of the mirror and C its centre of curvature. A point object is placed at C. It has a real image, also located at C. If the mirror is now filled with water, the image will be: <br />(A) real and will remain at C <br />(B) real and located at a point between C and µ<br />(C) virtual and located at a point between C and 0 <br />(D) real and located at a point between C and 0 <br /><br />Source 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-27707396443094727272009-10-12T04:31:00.000-07:002009-10-12T04:38:26.063-07:00IIT JEE Physics Final Revision Set 411. The electron in a hydrogen atom makes a transition n1 ®n2 where n1 and n2 are the principal quantum numbers of two states. Assume the Bohr model to be valid. The time period of the electron in the initial state is eight times that in the final state. The possible values of n1 and n2 are : <br />(A) n1 = 4, n2 = 2 (B)n1 = 8, n2 = 2 <br />(C) n1 = 8, n2 = 1 (D) n1 = 6, n2 = 3 <br /><br />2.A dielectric slab of thickness d is inserted in a parallel late capacitor whose negative plate is at x = 0 and positive plate is at x = 3d. The slab iis equidistant from the plates. The capacitor is given some charge. As x goes from 0 to 3d: <br />(A) the magnitude of the electric field remains the same <br />(B) the direction of the electric field remains the same <br />(C) the electric potential increases continuously <br />(D) the electric potential increases at first, then decreases and again increases. <br /><br /><br />3.The (x, y) coordinated of the corners of a square plate are (0, 0), (L, 0), (L, L) and (0, L). The edges of the plate are clamped and transverse standing waves re set up in it. If u (x, y) denotes the displacements of the plate at the point (x, y) at some instant of time, the possible expression (s) for u is (are) (a = positive constant): <br />(A) a cos (π x/2L) cos (π y/2L) <br />(B) a sin (π x/L) sin (π y/L) <br />(C) a sin (π x/L) sin (2π y/L) <br />(D) a cos (2π x/L) sin (π y/L) <br /><br />4. A force <strong>F</strong>= K(y <strong>î</strong> + x <strong>ĵ</strong>) (where K is a positive constant) acts on a particle moving in the xy plane. Starting from the origin, the particle is taken along the positive x-axis to the point (a, 0) and then parallel to the y-axis to the point (a, a). The total work done by the force F on the particle is: <br />(A) –2Ka² (B) 2Ka² <br />(C) –Ka² (D) Ka²<br /><br />5. A small square loop of wire of side l is placed inside a large square loop of wire of side L(L >> l). The loops are coplanar and their centres coincide. The mutual inductance of the system is proportional to : <br />(A) l/L (B) I²/L <br />(C) L/l (D) L²/l. <br /><br /><br />JEE 1998KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-80377986567940480712009-10-12T04:20:00.000-07:002009-10-12T04:31:03.587-07:00IIT JEE Physics Final Revision Set 401. Let v, vrms and vp respectively denote the mean speed, root mean square speed and most probable speed of the molecules in an ideal monoatomic gas at absolute temperature T. The mass of a molecule is m. Then : <br /><br />(A) no molecule can have a energy greater then √2 Vrms <br />(B) no molecule can have speed less thenVp/√2 <br />(C) Vp is l.t. V is l.t. Vrms <br />(D) the average kinetic energy of a molecule is 3/4 mvp² <br /><br />2. A string of length 0.4 ma and mass 10<sup>-2</sup> Kg is tightly clamped at its ends. The tension in the string is 1.6N. Identical wave pulses are produced at one end at equal intervals of time Dt. The minimum value of Dt, which allows constructive interference between successive pulses, is : <br />(A) 0.05s (B) 0.10 s <br />(C) 0.20 s <br />(D) 0.40 s <br /><br />3.A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence 450. The ray undergoes total internal reflection. If n is the refractive index of the medium with respect to air, select the possible value(s) of n from the following : <br />(A) 1.3 (B) 1.4 <br />(C) 1.5 (D) 1.6 <br /><br />4. Let mp be the mass of proton, mn the mass of neutron. M1 the mass of 20/10 Ne nucleus and M2 the mass of 40/20 Ca nucleus. Then : <br />(A) M2 = 2M1 (B) M2 > 2M1 <br />(C) M2 < 2M1 (D) M1 < 10 (mn + mp)<br /><br />5. A parallel monochromatic beam of light is incident normally on a narrow slit. A diffraction pattern is formed on a screen placed perpendicular to the direction of the incident beam. At the first minimum of the diffraction pattern, the phase difference between the rays coming from the two edges of the slit is: <br />(A) 0 (B) π /2 <br />(C) π (D) 2π <br /><br /><br />Source. 1998 JEEKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-91965019338799031632009-10-12T04:09:00.000-07:002009-10-12T04:20:04.988-07:00IIT JEE Physics Final Revision Set 391. 1. A transistor is used in common emitter mode as an amplifier, then : <br />(A)the base emitter junction is forward biased <br />(B)the base emitter junction is reverse biased <br />(C)the input signal is connected in series with the voltage applied to bias the base emitter junction. <br />(D)the input signal is connected in series with the voltage applied to bias the base collector junction. <br /><br />2. Water from a tap emerges vertically downwards with an initial speed of 1.0 m/s. The cross-sectional area of tap is 10^–4 m². Assume that the pressure is constant throughout the stream of water and that the flow is steady, the cross-sectional area of stream 0.15 m below the tap is : <br />(A) 5.0 × 10^–4 m² (B) 1.0 × 10^–4 m² <br />(C) 5.0 × 10^–5 m² (D) 2.0 × 10^–5 m² <br /><br />3. A real image of a distant object is formed by a planoconvex lens on its principal axis. Spherical aberration: <br />(A) is absent <br />(B) is smaller if the curved surface of the lens faces the object <br />(C) is smaller if the plane surface of the lens faces the object <br />(D) is the same whichever side of the lens faces the object <br /><br /><br />4. A vessel contains a mixture of one mole of oxygen and two moles of nitrogen at 300K. The ratio of the average rotational kinetic energy per O2 molecule to per N2 molecule is: <br />(A) 1 : 1 <br />(B) 1 : 2 <br />(C) 2 : 1 <br />(D) depends on the moment of inertia of the two molecules.<br /><br />5.Two particles, each of mass m and charge q, are attached to the two ends of a light rigid rod of length 2R. The rod is rotated at constant angular speed about a perpendicular axis passing through its centre. The ratio of the magnitudes of the magnetic moment of the system and its angular momentum about the centre of the rod is :<br />(A) q/2m (B) q/m <br />(C) 2q/m <br />(D) q/πm <br /><br />Source: JEE 1998KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-28139286561908431492009-10-12T03:45:00.000-07:002009-10-12T03:54:56.956-07:00IIT JEE Physics Final Revision Set 381. A cylindrical vessel of height 500 mm has an orifice (small hole) at its bottom. The orifice is initially closed and water is filled in it up to height H. Now the top is completely sealed with a cap and the orifice at the bottom is opened. Some water comes from the orifice and the water level in the vessel becomes steady with height of water column being 200 mm. Find the fall in height (in mm) of water level due to opening of the orifice.<br /><br /><br />[Take atmospheric pressure = 1.0 × 10^5 N/m², density of water = 1000 kg/m³ and g = 10 m/s². Neglect any effect of surface tension.]<br /><br />2. A 20 cm long string, having a mass of 1.0 g, is fixed at both the ends. The tension in the string is 0.5 N. The string is set into vibrations using an external vibrator of frequency 100 Hz. Find the separation (in cm) between the successive nodes on the string.<br /><br />3. A metal rod AB of length 10x has its one end A in ice at 0°C and the other end B in water at 100°C. If a<br />point P on the rod is maintained at 400°C, then it is found that equal amounts of water and ice evaporate and melt per unit time. The latent heat of evaporation of water is 540 cal/g and latent heat of melting of ice is 80 cal/g. If the point P is at a distance of λx from the ice end A, find the value of λ.<br />[Neglect any heat loss to the surrounding.]<br /><br />Source: 2009 JEE paper 2<br /><br />4. The moment of inertia of a uniform disc about its diameter is I. Then the moment of inertia about an axis passng through its centre and perpendicular to its plane is 2I. State true or false.<br /><br />5. A particle executes a linear simple harmonic motion of amplitude 25 cm and time period 3 s. What is the minimum time required for the particle to move between two points located at 12.5 cm on either side of equilibrium position?<br /><br />a. 2.5 s b. 1.5 sec c. 0.5 sec d. 3.0 sec<br /><br />4 and 5 (non JEE)KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-21947515134450808552009-10-12T02:59:00.000-07:002009-10-12T03:45:35.897-07:00IIT JEE Physics Final Revision Set 371. A student performed the experiment to measure the speed of sound in air using resonance air-column method. Two resonances in the air-column were obtained by lowering the water level. The resonance with the shorter air-column is the first resonance and that with the longer air-column is the second resonance.<br />Then -<br /><br />(A) the intensity of the sound heard at the first resonance was more than that at the second resonance<br />(B) the prongs of the tuning fork were kept in a horizontal plane above the resonance tube<br />(C) the amplitude of vibration of the ends of the prongs is typically around 1 cm<br />(D) the length of the air-column at the first resonance was somewhat shorter than 1/4th of the wavelength of the sound in air.<br /><br />2. Column II gives certain systems undergoing a process. Column I suggests changes in some of the<br />parameters related to the system. Match the statements in Column I to the appropriate process(es) from<br />Column II.<br /><br /><br /><br />Column I <br />(A) The energy of the system is increased <br />(B) Mechanical energy is provided to the system, which is converted into energy of random motion of its parts <br />(C) Internal energy of the system is converted into its mechanical energy<br />(D) Mass of the system is decreased <br /><br /><br /><br />Column II<br /><br />(p) System : A capacitor, initially uncharged<br />Process : It is connected to a battery<br /><br /><br />(q) System : A gas in an adiabatic container fitted with an adiabatic piston<br />Process : The gas is compressed by pushing the piston<br /><br />(r) System : A gas in a rigid container<br />Process : The gas gets cooled due to colder atmosphere surrounding it<br /><br />(s) System : A heavy nucleus, initially at rest<br />Process : The nucleus fissions into two fragments of nearly equal masses and some<br />neutrons are emitted<br />(t) System : A resistive wire loop<br />Process : The loop is placed in a time varying magnetic field perpendicular to its plane<br /><br /><br /><br />3. A solid sphere of radius R has a charge Q distributed in its volume with a charge density ρ = κr^a, where κ<br />and a are constants and r is the distance from its centre. If the electric field at r = R/2 is (1/8) times that at r = R, find the value of a.(in integer values)<br /><br />4. A steady current I goes through a wire loop PQR having shape of a right angle triangle with PQ = 3x,<br />PR = 4x and QR = 5x. If the magnitude of the magnetic field at P due to this loop is k = (μ<sub>0</sub>I/48πx), find the value of k (answer is to be in integers)<br /><br />5.Two soap bubbles A and B are kept in a closed chamber where the air is maintained at pressure 8 N/m². The radii of bubbles A and B are 2 cm and 4 cm, respectively. Surface tension of the soap-water used to make bubbles is 0.04 N/m. Find the ratio nB/nA, where nA and nB are the number of moles of air in bubbles<br />A and B, respectively. [Neglect the effect of gravity.]<br /><br />Source: 2009 JEE paper 2KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-8831548140209837482009-10-12T02:41:00.000-07:002009-10-12T02:49:43.325-07:00IIT JEE Physics Final Revision Set 36When a particle is restricted to move along x-axis between x = 0 and x = a, where a is of nanometer dimension, its energy can take only certain specific values. The allowed energies of the particle moving in such a restricted region, correspond to the formation of standing waves with nodes at its ends x = 0 and x = a. The wavelength of this standing wave is related to the linear momentum p of the particle according to the de Broglie relation. The energy of the particle of mass m is related to its linear momentum as E = p²/2m. Thus, the energy of the particle can be denoted by a quantum number 'n' taking values 1, 2, 3, . . . . . (n = 1, called the ground state) corresponding to the number of loops in standing wave.<br />Use the model described above to answer the following three questions for a particle moving in the line x = 0 to x = a.<br /><br />Take h = 6.6 × 10^–34 J-s and e = 1.6 × 10^–19 C.<br /><br />1. The allowed energy for the particle for a particular value of n is proportional to -<br />(A) a^(–2) (B) a^(–3/2) (C) a^(–1) (D) a^2<br /><br />2. If the mass of the particle is m = 1.0 × 10^–30 kg and a = 6.6 nm, the energy of the particle<br />in its ground state is closest to -<br />(A) 0.8 meV (B) 8 meV (C) 80 meV (D) 800 meV<br /><br />3. The speed of the particle, that can take discrete values, is proportional to -<br />(A) n^(–3/2) (B) n^(–1) (C) n^(1/2) (D) n<br /><br />Source: JEE 2009 paper 1<br /><br />4. A piece of wire is bent in the shape of a parabola y = kx² (y-axis vertical) with a bead of mass m on it. The bead can slide on the wire without friction. It stays at the lowest point of the parabola when the wire is at rest. The wire is now accelerated parallel to the x-axis with a constant acceleration a. The distance of the new equilibrium position of the bead, where the bead can stay at rest with respect to the wire, from the y-axis is –<br /><br /><br />a. a/gk b. a/2gk c. a/4gk d. 2a/gk<br /><br />5.Under the influence of the Coulomb field of charge +Q, a charge –q is moving around it in an elliptical<br />orbital. Find out the correct statement(s).<br />(A) The angular momentum of the charge – q is constant<br />(B) The linear momentum of the charge –q is constant<br />(C) The angular velocity of the charge –q is constant<br />(D) The linear speed of the charge –q is constant<br /><br />Source: JEE 2009 paper 2KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-91896944712866339202009-10-12T02:12:00.000-07:002009-10-12T02:33:48.806-07:00IIT JEE Physics Final Revision Set 351. If the resultant of all the external forces acting on a system of particles is zero, then from<br />an inertial frame, one can surely say that<br />(A) linear momentum of the system does not change in time<br />(B) kinetic energy of the system does not change in time<br />(C) angular momentum of the system does not change in time<br />(D) potential energy of the system does not change in time<br />(Multiple answers possible)<br /><br />2. A student performed the experiment of determination of focal length of a concave mirror<br />by u-v method using an optical bench of length 1.5 meter. The focal length of the mirror<br />used is 24 cm. The maximum error in the location of the image can be 0.2 cm. The 5 sets<br />of (u, v) values recorded by the student (in cm) are : (42, 56), (48, 48), (60, 40), (66, 33),<br />(78, 39). The data set(s) that cannot come from experiment and is(are) incorrectly<br />recorded, is (are)<br />(A) (42, 56) <br />(B) (48, 48) <br />(C) (66, 33) <br />(D) (78, 39)<br />(Multiple answers possible)<br /><br />3. Cv and Cp denote the molar specific heat capacities of a gas at constant volume and<br />constant pressure, respectively. Then<br />(A) Cp – Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas<br />(B) Cp + Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas<br />(C) Cp / Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas<br />(D) Cp . Cv is larger for a diatomic ideal gas than for a monoatomic ideal gas<br />(Multiple answers possible)<br /><br />Paragraph for Question Nos. 4 to 6<br /><br />Scientists are working hard to develop nuclear fusion reactor. Nuclei of heavy hydrogen, ²<sub>1</sub>H, known as deuteron and denoted by D, can be thought of as a candidate for fusion reactor. The D-D reaction is ²<sub>1</sub>H + ²<sub>1</sub>H → <sup>3</sup><sub>2</sub>He + n + energy. In the core of fusion reactor, a gas of heavy hydrogen is fully ionized into deuteron nuclei and electrons. This collection of ²<sub>1</sub>H 1 nuclei and electrons is known as plasma. The nuclei move randomly in the reactor core and occasionally come close enough for nuclear fusion to take place. Usually, the temperatures in the reactor core<br />are too high and no material wall can be used to confine the plasma. Special techniques are used which confine the plasma for a time t<sub>0</sub> before the particles fly away from the core. If n is the density (number/volume) of deuterons, the product nt<sub>0</sub> is called Lawson number. In one of the<br />criteria, a reactor is termed successful if Lawson number is greater than 5 × 10<sup>14</sup> s/cm<sup>3</sup>.<br /><br />It may be helpful to use the following. <br />Boltzmann constant k = 8.6 × 10<sup>-5</sup> eV/K;<br /><br />e²/πε<sub>0</sub> = 1.44 × 10<sup>-9</sup> eVm.<br /><br />4. In the core of nuclear fusion reactor, the gas becomes plasma because of –<br />(A) Strong nuclear force acting between the deuterons<br />(B) Coulomb force acting between the deuterons<br />(C) Coulomb force acting between deuteron-electron pairs<br />(D) the high temperature maintained inside the reactor core<br /><br />5. Assume that two deuteron nuclei in the core of fusion reactor at temperature T are<br />moving towards each other, each with kinetic energy 1.5 kT, when the separation<br />between them is large enough to neglect Coulomb potential energy. Also neglect any<br />interaction from other particles in the core. The minimum temperature T required for<br />them to reach a separation of 4 × 10<sup>-15</sup> m is in the range –<br /><br />a. 1.0 × 10<sup>0</sup>9 K is l.t. T is l.t. 2.0 × 10<sup>9</sup> K<br />b. 3.0 × 10<sup>0</sup>9 K is l.t. T is l.t. 4.0 × 10<sup>9</sup> K<br />c. 2.0 × 10<sup>0</sup>9 K is l.t. T is l.t. 3.0 × 10<sup>9</sup> K<br />d. 4.0 × 10<sup>0</sup>9 K is l.t. T is l.t. 5.0 × 10<sup>9</sup> K<br /><br />6. Results of calculations for four different designs of a fusion reactor using D-D reaction<br />are given below. Which of these is most promising based on Lawson criterion ?<br />(A) deuteron density = 2.0 × 10^12 cm–3, confinement time = 5.0 × 10^–3 s<br />(B) deuteron density = 8.0 × 10^14 cm–3, confinement time = 9.0 × 10^–1 s<br />(C) deuteron density = 4.0 × 10^23 cm–3, confinement time = 1.0 × 10^–11 s<br />(D) deuteron density = 1.0 × 10^24 cm–3, confinement time = 4.0 × 10^–12 s<br /><br /><br /><br />JEE 2009 paper 1KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-40509258073624390092009-10-12T01:45:00.000-07:002009-10-12T02:04:03.365-07:00IIT JEE Physics Final Revision Set 341. STATEMENT-1<br />For an observer looking out through the window of a fast moving train, the nearby objects appear to move<br />in the opposite direction to the train, while the distant object appear to be stationary.<br /><br />and<br />STATEMENT-2<br />If the observer and the object are moving at velocities <strong>V1</strong> and <strong>V2</strong> respectively with reference to a laboratory frame, the velocity of the object with respect to the observer is <strong>V2</strong>-<strong>V1</strong>.<br /><br />(A) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for<br />STATEMENT-1<br />(B) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for<br />STATEMENT-1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True.<br /><br />(Source: 2008 JEE paper 2)<br /><br /><br />2. The term that correct for the attractive forces present in a real gas in the van der Waals equation is -<br />(A) nb (B)an²/V² <br /><br />(C)-an²/V² (D) – nb<br /><br /><br />3. A block of base 10 cm × 10 cm and height 15 cm is kept on an inclined plane. The<br />coefficient of friction between them is √3 . The inclination θ of this inclined plane from the horizontal plane is gradually increased from 0º. Then<br /><br />(A) at θ = 30º, the block will start sliding down the plane<br />(B) the block will remain at rest on the plane up to certain θ and then it will topple<br />(C) at θ = 60º, the block will start sliding down the plane and continue to do so at higher angles<br />(D) at θ = 60º, the block will start sliding down the plane and on further increasing θ, it will topple at certain θ<br /><br /><br />4. Three concentric metallic spherical shells of radii R, 2R, 3R are given charges Q1, Q2, Q3 respectively. It is found that the surface charge densities on the outer surfaces of the shells are equal. Then, the ratio of the charges given to the shells, Q1 : Q2 : Q3 is-<br /><br />(A) 1 : 2 : 3 (B) 1 : 3 : 5 (C) 1 : 4 : 9 (D) 1 : 8 : 18<br /><br />5. A ball is dropped from a height of 20 m above the surface of water in a lake. The<br />refractive index of water is 4/3. A fish inside the lake, in the line of fall of the ball, is<br />looking at the ball. At an instant, when the ball is 12.8 m above the water surface, the<br />fish sees the speed of ball as-<br />(A) 9 m/s (B) 12 m/s (C) 16 m/s (D) 21.33 m/s<br /><br />Source: JEE 2009 paper 1KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-45273222307393425632009-10-12T01:33:00.000-07:002009-10-12T01:40:42.949-07:00IIT JEE Physics Final Revision Set 331. A vibrating string of certain length l under a tension T resonates with a mode corresponding to the first overtone (third harmonic) of an air column of length 75 cm inside a tube closed at one end. The string also generates 4 beats per second when excited along with a tuning fork of frequency n. Now when the tension<br />of the string is slightly increased the number of beats reduces to 2 per second. Assuming the velocity of sound in air to be 340 m/s, the frequency n of the tuning fork in Hz is<br /><br />(A) 344 (B) 336 (C) 117.3 (D) 109.3<br /><br />2. A radio active sample S1 having an activity of 5μCi has twice the number of nuclei as another sample S2 which has an activity of 10μCi. The half lives of S1 and S2 can be<br /><br />(A) 20 years and 5 years, respectively<br />(B) 20 years and 10 years, respectively<br />(C) 10 years each<br />(D) 5 years each<br /><br />3. STATEMENT - 1<br />It is easier to pull a heavy object than to push it on a level ground.<br />and<br />STATEMENT - 2<br />The magnitude of frictional force depends on the nature of the two surfaces in contact.<br />(A) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for<br />STATEMENT-1<br />(B) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for<br />STATEMENT-1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True.<br /><br />4. STATEMENT-1<br />For practical purposes the earth is used as a reference at zero potential in electrical circuits.<br />and<br />STATEMENT-2<br />The electrical potential of a sphere of radius R with charge Q uniformly distributed on the surface is given by Q/4πε<sub>0</sub>R<br /><br />(A) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for<br />STATEMENT-1<br />(B) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for<br />STATEMENT-1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True.<br /><br /><br />5. STATEMENT-1<br />The sensitivity of a moving coil galvanometer is increased by placing a suitable magnetic material as a<br />core inside the coil.<br />and<br />STATEMENT-2<br />Soft iron has a high magnetic permeability and cannot be easily magnetized or demagnetized.<br />(A) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for<br />STATEMENT-1<br />(B) STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for<br />STATEMENT-1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True.<br /><br /><br />Source: 2008 JEE Paper 2KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-32992062167437293282009-10-12T01:21:00.000-07:002009-10-12T01:26:57.681-07:00IIT JEE Physics Final Revision Set 321. STATEMENT -1<br />In a Meter Bridge experiment, null point for an unknown resistance is measured. Now, the unknown<br />resistance is put inside an enclosure maintained at a higher temperature. The null point can be obtained at<br />the same point as before by decreasing the value of the standard resistance.<br />and<br />STATEMENT-2<br />Resistance of a metal increases with increase in temperature.<br />(A) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is a correct explanation for<br />STATEMENT -1<br />(B) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is NOT a correct explanation<br />for STATEMENT -1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True<br /><br />2. STATEMENT – 1<br />Two cylinders, one hollow (metal) and the other solid (wood) with the same mass and identical<br />dimensions are simultaneously allowed to roll without slipping down an inclined plane from the same<br />height. The hollow cylinder will reach the bottom of the inclined plane first.<br />and<br />STATEMENT – 2<br />By the principle of conservation of energy, the total kinetic energies of both the cylinders are identical<br />when they reach the bottom of the incline.<br />(A) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is a correct explanation for<br />STATEMENT -1<br />(B) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is NOT a correct explanation<br />for STATEMENT -1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True<br /><br />3. STATEMENT – 1<br />The stream of water flowing at high speed from a garden hose pipe tends to spread like a fountain when<br />held vertically up, but tends to narrow down when held vertically down.<br />and<br />STATEMENT – 2<br />In any steady flow of an incompressible fluid, the volume flow rate of the fluid remains constant.<br />(A) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is a correct explanation for<br />STATEMENT -1<br />(B) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is NOT a correct explanation for STATEMENT -1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True<br /><br /><br />Paragraph<br />In a mixture of H and He+ gas (He+ is singly ionized He atom), H atoms and He+ ions are excited to their respective first excited states. Subsequently, H atoms transfer their total excitation energy to He+ ions (by collisions). Assume that the Bohr model of atom is exactly valid.<br /><br />4. The quantum number n of the state finally populated in He+ ions is<br />(A) 2 (B) 3 (C) 4 (D) 5<br /><br />5. The wavelength of light emitted in the visible region by He+ ions after collisions with H atoms is<br />(A) 6.5 × 10<sup>-7</sup> m (B) 5.6 × 10<sup>-7</sup> m<br />(C) 4.8 × 10<sup>-7</sup> m (D) 4.0 × 10<sup>-7</sup> m<br /><br />6. The ratio of the kinetic energy of the n = 2 electron for the H atom to that of He+ ion is<br /><br />a. 1/4 b. 1/2 c. 1 d. 2KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-41276119494279995252009-10-12T01:01:00.000-07:002009-10-12T01:13:19.943-07:00IIT JEE Physics Final Revision Set 311. An ideal gas is expanding such that PT2 = constant. The coefficient of volume expansion of the gas is<br /><br />a. 1/T b. 2/T c. 3/T d. 4/T<br /><br /><br />2. Two beams of red and violet colours are made to pass separately through a prism (angle of the prism is 60º). In the position of minimum deviation, the angle of refraction will be<br /><br />(A) 30º for both the colours (B) greater for the violet colour<br />(C) greater for the red colour (D) equal but not 30º for both the colours<br /><br />3. Which one of following statements is Wrong in the context of X-rays generated from a X- ray tube ?<br />(A) Wavelength of characteristic X-rays decreases when the atomic number of the target increases<br />(B) Cut-off wavelength of the continuous X-rays depends on the atomic number of the target<br />(C) Intensity of the characteristic X-rays depends on the electrical power given to the X-ray tube<br />(D) Cut-off wavelength of the continuous X-rays depends on the energy of the electrons in the X-ray tube<br /><br />4. In a Young’s double slit experiment, the separation between the two slits is d and the wavelength of the light is λ. The intensity of light falling on slit 1 is four times the intensity of light falling on slit 2. Choose the correct choice(s).<br /><br />(A) If d = λ, the screen will contain only one maximum<br />(B) If λ < d < 2λ, at least one more maximum (besides the central maximum) will be observed on the<br />screen<br />(C) If the intensity of light falling on slit 1 is reduced so that it becomes equal to that of slit 2, the<br />intensities of the observed dark and bright fringes will increase<br />(D) If the intensity of light falling on slit 2 is increased so that it becomes equal to that of slit 1, the intensities of the observed dark and bright fringes will increase<br /><br />5.STATEMENT – 1<br />An astronaut in an orbiting space station above the Earth experiences weightlessness.<br />and<br />STATEMENT – 2<br />An object moving around the Earth under the influence of Earth’s gravitational force is in a state of<br />‘free-fall’.<br />(A) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is a correct explanation for<br />STATEMENT -1<br />(B) STATEMENT – 1 is True, STATEMENT- 2 is True; STATEMENT -2 is NOT a correct explanation<br />for STATEMENT -1<br />(C) STATEMENT-1 is True, STATEMENT-2 is False<br />(D) STATEMENT-1 is False, STATEMENT-2 is True<br /><br /><br />Source JEE 2008 Paper 1KVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-9490122957753826772009-10-12T00:48:00.000-07:002009-10-12T00:58:18.066-07:00IIT JEE Physics Final Revision Set 30Paragraph<br />A cylinder of mass 1 kg is given heat of 20000J at atmospheric pressure. If initially temperature of cylinder is 20°C.<br /><br />1.Find final temperature of the cylinder.<br />2. Find the work done by the cylinder.<br />3 Find the change in internal energy of the cylinder.<br />(Given that Specific heat of cylinder= 400 J kg<sup>-1</sup> <sup>0</sup>C<sup>-1</sup>, Coefficient of volume expansion<br />= 9 × 10<sup>-5</sup> °C<sup>-1</sup>, Atmospheric pressure = 105 N/m2 and Density of cylinder = 9000 kg/m³)<br /><br /><br />Paragraph<br />In a moving coil galvanometer, torque on the coil can be expressed as τ = ki, where i is current through the wire and k is constant. The rectangular coil of the galvanometer having numbers of turns N, area A and moment of inertia I is placed in magnetic field B. <br /><br />4. Find k in terms of given parameters N, I, A and B.<br />5. Find the torsional constant of the spring, if a current i<sub>0</sub> produces a deflection of π/2 in the coil.<br />6. the maximum angle through which coil is deflected, if charge Q is passed through the coil almost instantaneously. (Ignore the damping in mechanical oscillations)<br /><br /><br />Source 2005 JEE MainsKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-88161671821124133822009-10-12T00:28:00.000-07:002009-10-12T00:44:51.313-07:00IIT JEE Physics Final Revision Set 291. A transverse harmonic disturbance is produced in a string. The maximum transverse velocity is 3 m/s and maximum transverse acceleration is 90 m/s². If the wave velocity is 20 m/s then find the waveform.<br /><br />2. A cylinder of mass m and radius R rolls down an inclined plane of inclination θ. Calculate the linear acceleration of the axis of cylinder.<br /><br />3. A long solenoid of radius a and number of turns per unit length n is enclosed by cylindrical shell of radius R, thickness d (d is very small compared to R) and length L. A variable current i = i<sub>0</sub>sin ωt flows through the coil. If the resistivity of the material of cylindrical shell is ρ, find the induced current in the shell.<br /><br />Paragraph:<br />Highly energetic electrons are bombarded on a target of an element containing 30 neutrons. The ratio of radii of nucleus to that of Helium nucleus is (14)<sup>1/3</sup>. <br /><br />4. Find atomic number of the nucleus.<br />5. Find the frequency of K<sub>α</sub> line of the X−ray produced. (R = 1.1 × 10<sup>7</sup> m<sup>-1</sup> and c = 3 ×10<sup>8</sup> m/s)<br /><br /><br />Source 2005 JEE MainKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-42861849370246642192009-10-12T00:18:00.000-07:002009-10-12T00:27:40.787-07:00IIT JEE Physics Final Revision Set 281. A whistling train approaches a junction. An observer standing at junction observes the frequency to be 2.2 KHz and 1.8 KHz of the approaching and the receding train. Find the speed of the train (speed of sound = 300 m/s)<br /><br />2. A conducting liquid bubble of radius a and thickness t (t <<a) is charged to potential V. If the bubble ollapses to a droplet, find the potential on the droplet.<br /><br />3. The potential energy of a particle of mass m is given by<br />V (x) = E0 when 0 is l.t. or = x is l.t. or = 1<br />V (x) = 0 when x>1<br />λ1 and λ2 are the de−Broglie wavelengths of the particle, when 0 ≤ x ≤ 1 and x > 1 respectively. If the total energy of particle is 2E0, find λ1/λ2.<br /><br />4. A U tube is rotated about one of it’s limbs<br />with an angular velocity ω. Find the difference<br />in height H of the liquid (density ρ) level,<br />where diameter of the tube d << L.<br /><br />5. The side of a cube is measured by vernier callipers (10 divisions of a vernier scale coincide with 9 divisions of main scale, where 1 division of main scale is 1 mm). The main scale reads 10 mm and first division of vernier scale coincides with the main scale. Mass of the cube is 2.736 g. Find the density of the cube in appropriate significant figures.<br /><br /><br />Source 2005 JEE MainsKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-40420785358659048152009-10-12T00:12:00.000-07:002009-10-12T00:18:44.315-07:00IIT JEE Physics Final Revision Set 271. A spherical ball of radius R, is floating in a liquid with half of its volume submerged in the liquid. Now the ball is displaced vertically by small distance inside the liquid. Find the frequency of oscillation of ball.<br />----<br />Paragraph:<br />A point object is moving with velocity 0.01 m/s on principal axis towards a convex lens of focal length 0.3m. When object is at a distance of 0.4 m from the lens, find<br /><br />2. rate of change of position of the image, and<br />3. rate of change of lateral magnification of image.<br /><br /><br />4. A cubical block is floating inside a bath. The temperature of system<br />is increased by small temperature ΔT. It was found that the depth<br />of submerged portion of cube does not change. Find the relation<br />between coefficient of linear expansion (α) of the cube and volume<br />expansion of liquid (γ).<br /><br />5. In a Young’s double slit experiment light consisting of two wavelengths λ1 = 500 nm and λ2 = 700 nm is incident normally on the slits. Find the distance from the central maxima where the maximas due to two wavelengths coincide for the first time after central maxima. (Given D/d = 1000) where D is the distance between the slits and the screen and d is the separation between the slits.<br /><br />Source: 2004 MainsKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-91308880890135121372009-10-12T00:06:00.000-07:002009-10-12T00:12:34.851-07:00IIT JEE Physics Final Revision Set 261. The age of a rock containing lead and uranium is equal to 1.5 × 10<sup>9</sup> yrs. The uranium is decaying into lead with half life equal to 4.5 × 10<sup>9</sup> yrs. Find the ratio of lead to uranium present in the rock, assuming initially no lead was present in the rock. (Given 2<sup>1/3</sup> = 1.259)<br /><br />2. An inductor of inductance (L) equal to 35 mH<br />and resistance (R) equal to 11 Ω are connected<br />in series to an AC source. The rms voltage of<br />a.c. source is 220 volts and frequency is 50 Hz.<br />Find the peak value of current in the circuit.<br /><br />Two identical blocks A and B are placed on a rough inclined plane of<br />inclination 45°. The coefficient of friction between block A and incline is<br />0.2 and that of between B and incline is 0.3. The initial separation between<br />the two blocks is √2 m. The two blocks are released from rest, then find<br /><br /><br />3. the time after which front faces of both blocks come in same line <br />4. the distance moved by each block for attaining above position.<br /><br /><br />5. In a photoelectric setup, the radiations from the Balmer series of hydrogen atom are incident on a metal<br />surface of work function 2eV. The wavelength of incident radiations lies between 450 nm to 700 nm. Find<br />the maximum kinetic energy of photoelectron emitted.<br />(Given hc/e = 1242 eV-nm).<br /><br />Source 2004 jee mainKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0tag:blogger.com,1999:blog-2868404081384742161.post-21572132282407002302009-10-11T23:56:00.000-07:002009-10-12T00:06:33.341-07:00IIT JEE Physics Final Revision Set 251. In Searle’s apparatus diameter of the wire was measured 0.05 cm by screw gauge of least count 0.001 cm.The length of wire was measured 110 cm by meter scale of least count 0.1 cm. An external load of 50 N was applied. The extension in length of wire was measured 0.125 cm by micrometer of least count 0.001 cm. Find the maximum possible error in measurement of young’s modulus.<br /><br />2. Two infinitely large sheets having charge densities σ1 and σ2<br />respectively (σ1 > σ2) are placed near each other separated by<br />distance ‘d’. A charge ‘Q’ is placed in between two plates such that<br />there is no effect on charge distribution on plates. Now this charge<br />is moved at an angle of 45° with the horizontal towards plate having<br />charge density σ2 by distance ‘a’ (a is l.t. d). Find the work done by<br />electric field in the process.<br /><br />3. An α -particle and a proton are accelerated from rest through same potential difference and both enter into a uniform perpendicular magnetic field. Find the ratio of their radii of curvature.<br /><br />4. A small ball of radius ‘r’ is falling in a viscous liquid under gravity. Find the dependency of rate of heat produced in terms of radius ‘r’ after the drop attains terminal velocity.<br /><br />5. A screw gauge of pitch 1mm has a circular scale divided into 100 divisions. The diameter of a wire is to be measured by above said screw gauge. The main scale reading is 1mm and 47th circular division coincides with main scale. Find the curved surface area of wire in true significant figures. (Given the length of wire<br />is equal to 5.6 cm and there is no zero-error in the screw gauge.)<br /><br /><br />Source: 2004 JEE mainsKVSSNraohttp://www.blogger.com/profile/05748254811752425330noreply@blogger.com0