In a transformer, the coefficient of mutual inductance between the primary and the secondary coil is 0.2 henry. When the current changes by 5 ampere/second in the primary, the induced e.m.f. in the secondary will be
|
(a) 5 V |
(b) 1 V |
(c) 25 V |
(d) 10 V |
(b) 1 V
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Radiations of intensity 0.5
are striking a metal plate. The pressure on the plate is
|
(a) 0.166 |
(b) 0.332 |
|
(c) 0.111 |
(d) 0.083 |
Focal length of a converging lens in air is R. If it is dipped in water of refractive index 1.33, then its focal length will be around (Refractive index of lens material is 1.5)
|
(a) R |
(b) 2R |
(c) 4R |
(d) R / 2 |
In a PN-junction diode not connected to any circuit
|
(a) The potential is the same everywhere |
|
(b) The P-type is a higher potential than the N-type side |
|
(c) There is an electric field at the junction directed from the N- type side to the P- type side |
|
(d) There is an electric field at the junction directed from the P-type side to the N-type side |
Two identical metal plates show photoelectric effect by a light of wavelength 
falls on plate A and 
on plate B (
. The maximum kinetic energy is
|
(a) 2 |
(b) |
(c) |
(d) |
