Explanation:
(d) is based on Joule's Law.
Rest are electrostatic phenomenon.
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For television broadcasting, the frequency employed is normally
|
(a) 30-300 MHz |
(b) 30-300 GHz |
(c) 30-300 KHz |
(d) 30-300 Hz |
A fish is a little away below the surface of a lake. If the critical angle is 49°, then the fish could see things above the water surface within an angular range of θ° where
|
(a) θ = 49° |
(b) θ = 90° |
(c) θ = 98° |
(d) θ = 24 |
Refractive index for a material for infrared light is
|
(a) Equal to that of ultraviolet light |
|
(b) Less than for ultraviolet light |
|
(c) Equal to that for red colour of light |
|
(d) Greater than that for ultraviolet light |
A straight conductor of length 0.4 m is moved with a speed of 7 m/s perpendicular to the magnetic field of intensity of 0.9 Wb/m2. The induced e.m.f. across the conductor will be
|
(a) 7.25 V |
(b) 3.75 V |
(c) 1.25 V |
(d) 2.52 V |
In a triode valve the amplification factor is 20 and mutual conductance is 10–3 mho. The plate resistance is
|
(a) 2 × 103 W |
(b) 4 × 103 W |
(c) 2 ×104 W |
(d) 2 ×104 W |
If the ratio of amplitude of two waves is 4 : 3, then the ratio of maximum and minimum intensity is
|
(a) 16 : 18 |
(b) 18 : 16 |
(c) 49 : 1 |
(d) 94 : 1 |
A cell of internal resistance r is connected to an external resistance R. The current will be maximum in R, if
|
(a) R = r |
(b) R < r |
(c) R > r |
(d) R = r/2 |
