- A8
- B6
- C15
- D∞
Explanation:
Number of spectral lines in hydrogen atom ∞.
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An electron and a proton with equal momentum enter perpendicularly into a uniform magnetic field, then
|
(a) The path of proton shall be more curved than that of electron |
|
(b) The path of proton shall be less curved than that of electron |
|
(c) Both are equally curved |
|
(d) Path of both will be straight line |
The average kinetic energy of the thermal neutrons is of the order of (Boltzmann's constant
|
(a) 0.03 eV |
(b) 3 eV |
(c) 3 KeV |
(d) 3 MeV |
Period of revolution increases in the order of
|
(a) Saturn, Uranus, Venus |
(b) Mars, Saturn, Pluto |
|
(c) Mercury, Neptune, Mars |
(d) Mars, Jupiter, Venus |
Rest mass energy of an electron is 0.54 MeV. If velocity of the electron is 0.8 c, then K.E. of the electron is
|
(a) 0.36 MeV |
(b) 0.41 MeV |
(c) 0.48 MeV |
(d) 1.32 MeV |
A transformer with efficiency 80% works at 4 kW and 100 V. If the secondary voltage is 200 V, then the primary and secondary currents are respectively
|
(a) 40 A, 16 A |
(b) 16 A, 40 A |
(c) 20 A, 40 A |
(d) 40 A, 20 A |
The image formed behind a mirror and a virtual image:
The unit of focal power of a lens is
|
(a) Watt |
(b) Horse power |
(c) Dioptre |
(d) Lux |