Question

A $10\, m$ long horizontal wire extends from North East to South West. It is falling with a speed of $5.0\,ms^{-1}$, at right angles to the horizontal component of the earth's magnetic field, of $0.3 \times 10^{-4}\,Wb/m^2$. The value of the induced emf in wire is :

• A. $2.5 \times 10^{-3} V$
• B. $1.1 \times 10^{-3}V$
• C. $0.3 \times 10^{-3} V$
• D. $1.5 \times 10^{-3} V$

Answer 1

The Correct Option is B

Induced emf $= Bv \ell \sin 45 $
$= 0.3 \times 10^{-4} \times 5 \times 10 \times \frac{1}{\sqrt{2}} $
= $1.1 \times 10^{-3} V$