- A$\text{zero}$
- B$\pi$
- C$-\frac{\pi}{2}$
- D$\frac{\pi}{2}$
Explanation:
In a purely capacitive circuit, current leads the voltage by $-\frac{\pi}{2}$
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When the temperature of silicon sample is increased from 27℃ to 100℃, the conductivity of silicon will be
|
(a) Increased |
(b) Decreased |
(c) Remain same |
(d) Zero |
What is the coefficient of mutual inductance when the magnetic flux changes by 2
and change in current is 0.01A
|
(a) 2 henry |
(b) 3 henry |
(c) |
(d) Zero |
The curve drawn between velocity and frequency of photon in vacuum will be a
|
(a) Straight line parallel to frequency axis |
|
(b) Straight line parallel to velocity axis |
|
(c) Straight line passing through origin and making an angle of 45o with frequency axis |
|
(d) Hyperbola |
The phenomenon utilised in an optical fibre is
|
(a) Refraction |
(b) Interference |
|
(c) Polarization |
(d) Total internal reflection |
An air filled parallel plate capacitor has capacity C. If distance between plates is doubled and it is immersed in a liquid then capacity becomes twice. Dielectric constant of the liquid is
|
(a) 1 |
(b) 2 |
(c) 3 |
(d) 4 |
If the operating potential of an X-ray tube is 50 kV, the velocity of X-rays coming out of it is
|
(a) 4 |
(b) 3 |
(c) |
(d) 3 m/s |
When a plane mirror is rotated through an angle θ then the reflected ray turns through the angle 2θ then the size of the image
| (a) Is doubled | (b) Is halved | (c) Remains the same | (d) Becomes infinite |
If the energy of the photon is increased by a factor of 4, then its momentum
|
(a) Does not change |
(b) Decreases by a factor of 4 |
|
(c) Increases by a factor of 4 |
(d) Decreases by a factor of 2 |