- A−75 and 200
- B0 and 75
- C−25 and 300
- D−40 and 1000
Explanation:
Semiconductor can be used safely between temperature 0 and 75.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A photocell stops emission if it is maintained at 2V negative potential. The energy of most energetic photoelectron is
|
(a) 2eV |
(b) 2J |
(c) 2kJ |
(d) 2keV |
A calcite crystal is placed over a dot on a piece of paper and rotated, on seeing through the calcite one will be see
|
(a) One dot |
(b) Two stationary dots |
|
(c) Two rotating dots |
(d) One dot rotating about the other |
An electron of mass initially at rest moves through a certain distance in a uniform electric field in time
. A proton of mass
also initially at rest takes time
to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio of
is nearly equal to
|
(a) 1 |
(b) |
(c) |
(d) 1836 |
The figure shows three circuits with identical batteries, inductors, and resistors. Rank the circuits according to the current through the battery (i) just after the switch is closed and (ii) a long time later, greatest first

|
(a) (i) |
|
(b) (i) |
|
(c) (i) |
|
(d) (i) |

The energy of a photon is E = hv and the momentum of photon p =
, then the velocity of photon will be
|
(a) E/p |
(b) Ep |
(c) |
(d) 3 |
When a white light passes through a hollow prism, then
|
(a) There is no dispersion and no deviation |
(b) Dispersion but no deviation |
|
(c) Deviation but no dispersion |
(d) There is dispersion and deviation both |
The phenomenon by which light travels in an optical fibres is
|
(a) Reflection |
(b) Refraction |
|
(c) Total internal reflection |
(d) Transmission |
An electric bulb is rated 60W, 220V. The resistance of its filament is
|
(a) 708 W |
(b) 870 W |
(c) 807 W |
(d) 780 W |
According to the pulsating theory the expansion and contraction of the universe repeats after every
|
(a) 11 years |
(b) 8 billion years |
(c) 8 million years |
(d) 80 billion years |