Question

A horizontal straight wire 10 m long extending from east to west is falling with a speed of 5.0 ms^-1 at right angles to the horizontal component of the earth’s magnetic field 0.3 × 10^-4Wbm².

1. What is the instantaneous value of the e.m.f? induced in the wire?

2. What is the direction of the e.m.f.? 

3. Which end of the wire is at the higher electrical potential?

Answer 1

I – 10m, v = 5.0ms^-1 , B = 0.30 × 10^-4 Wbm² 

1. Instantaneous value of e.m.f. induced

e = B lv

= 0.30 × 10^-4 × 10 × 5.0

or e = 1.5 × 10^-3 V. 

2. The direction of e.m.f. is from east to west.

3. Since the current is owing from east to west so the eastern end is at higher potential.