- APhotoelectrons absorb and emit photons
- BThe velocity of light is the same for all observers
- CMass and energy are intra- convertible
- DEnergy and momentum are conserved
Explanation:
The main postulate of Einstein's special theory of relativity is that the speed of light is constant and equal to c in all the inertial frames i.e the velocity of light is same for all observers.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A step up transformer connected to a 220 V AC line is to supply 22 kV for a neon sign in secondary circuit. In primary circuit a fuse wire is connected which is to blow when the current in the secondary circuit exceeds 10 mA. The turn ratio of the transformer is
|
(a) 50 |
(b) 100 |
(c) 150 |
(d) 200 |
Three charges each of magnitude q are placed at the corners of an equilateral triangle, the electrostatic force on the charge placed at the center is (each side of triangle is L)
|
(a) Zero |
(b) |
(c) |
(d) |
By a cell a current of 0.9 A flows through 2 ohm resistor and 0.3 A through 7 ohm resistor. The internal resistance of the cell is
|
(a) 0.5 Ω |
(b) 1.0 Ω |
(c) 1.2 Ω |
(d) 2.0 Ω |