- ALight requires a material medium to travel from one place to another.
- BLight does not require a material medium to propagate.
- CLight has mass but it is negligible.
- DLight waves are longitudinal wave.
Explanation:
Light does not need medium to travel. Its an electromagnetic wave. All electromagnetic waves travel independent of medium.
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The transconductance of a triode amplifier is 2.5 mili mho having plate resistance of 20 KW, amplification 10. Find the load resistance
|
(a) 5 kW |
(b) 25 kW |
(c) 20 kW |
(d) 50 kW |
The distance of the eye-lens from the retina is x. For a normal eye, the maximum focal length of the eye-lens:
A coil having an inductance of 0.5 H carries a current which is uniformly varying from zero to 10 ampere in 2 second. The e.m.f. (in volts) generated in the coil is
|
(a) 10 |
(b) 5 |
(c) 2.5 |
(d) 1.25 |
A dip needle vibrates in the vertical plane perpendicular to the magnetic meridian. The time period of vibration is found to be 2 seconds. The same needle is then allowed to vibrate in the horizontal plane and the time period is again found to be 2 seconds. Then the angle of dip is
|
(a) 0o |
(b) 30o |
(c) 45o |
(d) 90o |
Two short magnets with their axes horizontal and perpendicular to the magnetic meridian are placed with their centres 40 cm east and 50 cm west of magnetic needle. If the needle remains undeflected, the ratio of their magnetic moments
is
|
(a) 4 : 5 |
(b) 16 : 25 |
(c) 64 : 125 |
(d) 2 : |
Larger aperture of objective lens in an astronomical telescope:
If a copper ring is moved quickly towards south pole of a powerful stationary bar magnet, then
|
(a) Current flows through the copper ring |
|
(b) Voltage in the magnet increase |
|
(c) Current flows in the magnet |
|
(d) Copper ring will get magnetised |
A 60 watt bulb operates on 220V supply. The current flowing through the bulb is
|
(a) 11/3 amp |
(b) 3/11 amp |
(c) 3 amp |
(d) 6 amp |