Q. There is an arial 1 m long in a car. It is moving from east to west with a velocity of 100 km$h^{- 1}$. If the horizontal component of earth’s magnetic field is 0.18 gauss, this induced emf is nearly
A) 0.5 mV
B) 0.25 mV
C) 0.75 mV
D) 1 mV
Explanation
(a) $l = 1\ m,\ v = 100\ kmh^{- 1}$
$= \ \frac{100 \times 1000}{60 \times 60} = \frac{250}{9}ms^{- 1}$
$e\ = Blv = 0.18 \times 10^{- 4} \times 1 \times \frac{250}{9} = 5 \times 10^{- 4}\ $V
= 0.5 mV
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.