MCQ
The radius of a wavefront as the waves propagate:
- ADecreases
- BIncreases
- CBecomes zero
- DSometimes decreases and sometimes increases.
Explanation:
As the waves propagates, it goes on creating secondary sources of light, resulting in increase in its radius.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Consider the following two statements:
The resistance of the series combination of two resistance is S. When they are joined in parallel the total resistance is P. If S = nP, then the minimum possible value of n is
|
(a) 4 |
(b) 3 |
(c) 2 |
(d) 1 |
At a distance of 10 cm from a long straight wire carrying current, the magnetic field is 0.04 T. At the distance of 40 cm, the magnetic field will be
|
(a) 0.01 T |
(b) 0.02 T |
(c) 0.08 T |
(d) 0.16 T |
A parallel beam of monochromatic light of wavelength 5000 Å is incident normally on a single narrow slit of width 0.001 mm. The light is focused by a convex lens on a screen placed on the focal plane. The first minimum will be formed for the angle of diffraction equal to
|
(a) 0o |
(b) 15o |
(c) 30o |
(d) 60o |
By Huygen's wave theory of light, we cannot explain the phenomenon of
|
(a) Interference |
(b) Diffraction |
(c) Photoelectric effect |
(d) Polarisation |
The resistance of a 5 cm long wire is 10 W. It is uniformly stretched so that its length becomes 20 cm. The resistance of the wire is
|
(a) 160 W |
(b) 80 W |
(c) 40 W |
(d) 20 W |
For a glass prism, the angle of minimum deviation will be smallest for the light of: