- AEinstein mass-energy relation.
- BEinstein theory of relativity
- CPhotoelectric effect
- DNone of the above
Explanation:
Doppler effect refers to the change in wave frequency during the relative motion between a wave source and it's observer by considering that the Velocity of the observer with respect to the source velocity is negligible.
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Two different coils have self-inductance
,
. The current in one coil is increased at a constant rate. The current in the second coil is also increased at the same rate. At a certain instant of time, the power given to the two coils is the same. At that time the current, the induced voltage and the energy stored in the first coil are
and
respectively. Corresponding values for the second coil at the same instant are
and
respectively. Then
|
(a) |
(b) |
(c) |
(d) a, b, c |
A particle of mass M at rest decays into two particles of masses m1 and m2, having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles,
is
|
(a) |
(b) |
(c) 1.0 |
(d) |
The output of a NAND gate is 0
|
(a) If both inputs are 0 |
|
(b) If one input is 0 and the other input is 1 |
|
(c) If both inputs are 1 |
|
(d) Either if both inputs are 1 or if one of the inputs is 1 and the other 0 |
A copper wire has a square cross-section, 2.0 mm on a side. It carries a current of 8 A and the density of free electrons is 8 . The drift speed of electrons is equal to
|
(a) 0.156 × |
(b) 0.156 × |
(c) 3.12 × |
(d) 3.12 × |
A metallic square loop ABCD is moving in its own plane with velocity v in a uniform magnetic field perpendicular to its plane as shown in the figure. An electric field is induced

|
(a) In AD, but not in BC |
(b) In BC, but not in AD |
|
(c) Neither in AD nor in BC |
(d) In both AD and BC |
A parallel plate air capacitor is charged to a potential difference of V. After disconnecting the battery, distance between the plates of the capacitor is increased using an insulating handle. As a result, the potential difference between the plates
|
(a) Decreases |
(b) Increases |
(c) Becomes zero |
(d) Does not change |
A 4 mF capacitor, a resistance of 2.5 MW is in series with 12 V battery. Find the time after which the potential difference across the capacitor is 3 times the potential difference across the resistor. [Given ln(2)= 0.693]
|
(a) 13.86 s |
(b) 6.93 s |
(c) 7 s |
(d) 14 s |