MCQ
The equation E = pc is valid:
- AFor an electron as well as for a photon.
- BFor an electron but not for a photon.
- CFor a photon but not for an electron.
- DNeither for an electron nor for a photon.
Explanation:
The equation E = pc is valid for a particle with zero rest mass. The rest mass of a photon is zero, but the rest mass of an electron is not zero. So, the equation will be valid for photon, and not electron.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
The light reflected by a plane mirror may form a real image
|
(a) If the rays incident on the mirror are diverging |
|
(b) If the rays incident on the mirror are converging |
|
(c) If the object is placed very close to the mirror |
|
(d) Under no circumstances |
Masses of 3 wires of same metal are in the ratio 1 : 2 : 3 and their lengths are in the ratio 3 : 2 : 1. The electrical resistances are in ratio
|
(a) 1 : 4 : 9 |
(b) 9 : 4 : 1 |
(c) 1 : 2 : 3 |
(d) 27 : 6 : 1 |
Two thin lenses, one of focal length + 60 cm and the other of focal length – 20 cm are put in contact. The combined focal length is
|
(a) + 15 cm |
(b) – 15 cm |
(c) + 30 cm |
(d) –30 cm |
A person cannot see objects clearly beyond 2.0 m. The power of lens required to correct his vision will be
|
(a) + 2.0 D |
(b) – 1.0 D |
(c) + 1.0 D |
(d) – 0.5 D |
In semiconductors at a room temperature
|
(a) The valence band is partially empty and the conduction band is partially filled |
|
(b) The valence band is completely filled and the conduction band is partially filled |
|
(c) The valence band is completely filled |
|
(d) The conduction band is completely empty |
According to Maxwell’s hypothesis, a changing electric field gives rise to
|
(a) An e.m.f. |
(b) Electric current |
(c) Magnetic field |
(d) Pressure radiant |
The light when enters the human eye experiences most of the refraction while passing through
|
(a) Cornea |
(b) Aqueous humour |
(c) Vitrous humour |
(d) Crystalline lens |