A straight conductor of length 0.4 m is moved with a speed of 7 m-1 perpendicular to a magnetic field of induction 0.9 Wb/m2 and the length of the conductor. The induced e.m.f. across the conductor is:
(a) 25.2 V
(b) 5.04 V
(c) 2.52 V
(d) 1.26 V
Answer & explanation
Correct answer: option 3
The induced emf (ε) in a conductor moving in a magnetic field is -
$ε=B.l.v$ [Faraday's Law]
where,
B, Magnetic field = 0.9 T
$l$, length of conductor = 0.4 m
v, velocity of conductor = 7 m/s
$ε=0.9×0.4×7$
$=2.52V$