When a compact disc is illuminated by a source of white light. Coloured 'lanes' are observed. This is due to
|
(a) Dispersion |
(b) Diffraction |
(c) Interference |
(d) Refraction |
(b) Diffraction
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A moving charge will gain energy due to the application of
|
(a) Electric field |
(b) Magnetic field |
(c) Both of these |
(d) None of these |
The average e.m.f. induced in a coil in which a current changes from 0 to 2 A in 0.05 s is 8 V. The self inductance of the coil is
|
(a) 0.1 H |
(b) 0.2 H |
(c) 0.4 H |
(d) 0.8 H |
Using a bar magnet P, a vibration magnetometer has time period 2seconds. When a bar Q (identical to P in mass and size) is placed on top of P, the time period is unchanged. Which of the following statements is true
| (a) Q is of non-magnetic material |
|
(b) Q is a bar magnet identical to P, and its north pole placed on top of P's north pole |
| (c) Q is of unmagnetized ferromagnetic material |
| (d) Nothing can be said about Q's properties |
It is desired to photograph the image of an object placed at a distance of 3m from the plane mirror. The camera which is at a distance of 4.5 m from the mirror should be focussed for a distance of
| (a) 3m | (b) 4.5m | (c) 6m | (d) 7.5 m |
Davission and Germer experiment proved
|
(a) Wave nature of light |
(b) Particle nature of light |
|
(c) Both (a) and (b) |
(d) Neither (a) nor (b) |