IIT JEE Physics Final Revision Set 10

1. Consider a neutral conducting sphere. A
positive point charge is placed outside
the sphere. The net charge on the sphere
is then,
1. Negative and distributed uniformly
over the surface of the sphere.
2. Negative and appears only at the point
on the sphere closest to the point charge
3. Negative and distributed nonuniformly
over the entire surface of the
sphere
4. Zero

2. STATEMENT – 1
The formula connecting u, v and f for a
spherical mirror is valid only for mirrors
whose sizes are very small compared to
their radii of curvature.
because
STATEMENT-2
Laws of reflection are strictly valid for
plane surfaces, but not for large
spherical surfaces.
a. Statement-I is true, Statement-2 is
True ; Statement-2 is a correct
explanation for Statement-I
b. Statement-1 is true, Statement-2 is
True ; Statement-2 is NOT a correct
explanation for Statement-I.
c. Statement-1 is True, Statement-2 is
False.
d. Statement-1 is False, Statement-2 is
True.


3.STATEMENT-1: If the accelerating
potential in an X-ray tube is increased,
the wavelengths of the characteristic Xrays
do not change. Because
STATEMENT-2 : When an electron
beam strikes the target in an X-ray tube,
part of the kinetic energy is converted
into X-ray energy.
a. Statement-1 is True, Statement-2 is
True; Statement-2 is a correct
explanation for Statement-1.
b. Statement-1 is True, Statement-2 is
True; Statement-2 is NOT a correct
explanation for Statement-1.
c. Statement-1 is True, Statement-2 is
False.
d. Statement-1 is False, Staement-2 is
True.

4. STATEMENT-1 : A block of mass m
starts moving on a rough horizontal
surface with a velocity v. It stops due to
friction between the block and the
surface after moving through a certain
distance. The surface is now tilted to an
angle of 30° with the horizontal and the
same block is made to go up on the
surface with the same initial velocity v.
The decrease in the mechanical energy
in the second situation is smaller than
that in the first situation. Because
STATEMENT-2 : The coefficient of
friction between the block and the
surface decreases with the increase in
the angle of inclination.
a. Statement-1 is True, Statement-2 is
True ; Statement-2 is a correct
explanation for statement-1.
b. Statement-1 is True, Statement-2 is
True; Statement-2 is NOT a correct
explanation for statement-1.
c. Statement-1 is True, Statement-2 is
False.
d. Statement-1 is False, Statement-2 is
True.

Source: 2007 JEE paper 1