Question

A horizontal straight wire 10m long extending from east to west is falling with a speed of 5.0 m/s at right angles to the horizontal component of earth's magnetic field $0.3\times {10}^{-4}$ tesla. The emf induced across the ends of wire is

• A. 1.5 mV with higher potential at eastern end
• B. 1.5 mV with higher potential at western end
• C. 0.75 mV with higher potential at eastern end
• D. Zero

Answer 1

The correct option is A 1.5 mV with higher potential at eastern end

$e=B_{H}lu$
$=0.3\times {10}^{-4}\times 10\times 5$
$=15\times {10}^{-4}$
$=1.5\times {10}^{-3}v$
= 1.5 mV with higher potential at eastern end