1. In a resonance tube with tuning fork of frequency 512Hz, first resonance occurs at water level equal to 30.3 cm and second resonance occurs at 63.7 cm. The maximum possible error in the speed of sound is
(A) 51.2 cm/s (B) 102.4 cm/s
(C) 204.8 cm/s (D) 153.6 cm/s
2. A thin concave and a thin convex lens are in contact. The ratio of the magnitude of power of two lenses is 2/3
and focal length of combination is 30cm, then the focal length of individual lenses are
(A) – 15 cm, 10 cm (B) – 75 cm, 50 cm
(C) 75 cm, - 50 cm (D) 75 cm, 50 cm
3. Which of the following process does not occur through convection
(A) Boiling of water (B) Land breeze and Sea breeze
(C) Circulation of air around furnace (D) Heating of glass bulb through filament
4. In YDSE, an electron beam is used to obtain interference pattern. If speed of electron is increased then
(A) no interference pattern will be observed.
(B) distance between two consecutive fringes will increase.
(C) distance between two consecutive fringes will decrease.
(D) distance between two consecutive fringes remains same.
5. A spherical body of area A and emissivity e = 0.6 is kept inside a perfectly black body. Total heat radiated by the body at temperature T
(A) 0.4 e AT4 (B) 0.8eAT4
(C) 0.6 eAT4 (D) 1.0eAT4
source 2005 JEE screening