Two infinitely long parallel conducting plates having surface charge densities +σ and -σ respectively, are separated by a small distance. The medium between the plates is vacuum. If 
is the dielectric permittivity of vacuum, then the electric field in the region between the plates is
|
(a) 0 volts/meter |
(b) |
(c) |
(d) |
(c) 
volts/meter
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A plane mirror makes an angle of 30° with horizontal. If a vertical ray strikes the mirror, find the angle between mirror and reflected ray
| (a) 30° | (b) 45° | (c) 60° | (d) 90° |
The relative permeability (
of a ferromagnetic substance varies with temperature (T) according to the curve
|
(a) A |
(b) B |
(c) C |
(d) D |
The work done in bringing a 20 coulomb charge from point A to point B for distance 0.2m is 2J. The potential difference between the two points will be (in volt)
|
(a) 0.2 |
(b) 8 |
(c) 0.1 |
(d) 0.4 |
Assertion : If the temperature of a semiconductor is increased then it's resistance decreases.
Reason : The energy gap between conduction band and valence band is very small
|
(a) If both assertion and reason are true and the reason is the correct explanation of the assertion. |
|
(b) If both assertion and reason are true but reason is not the correct explanation of the assertion. |
|
(c) If assertion is true but reason is false. |
|
(d) If the assertion and reason both are false. |
The transfer ratio of a transistor is 50. The input resistance of the transistor when used in the common-emitter configuration is 1 KW. The peak value for an A.C input voltage of 0.01 V peak is
|
(a) 100 mA |
(b) 0.01 mA |
(c) 0.25 mA |
(d) 500 mA |
