Question:
A $10 \mathrm{~m}$ long horizontal wire extends from North East to South West. It is falling with a speed of $5.0 \mathrm{~ms}^{-1}$, at right angles to the horizontal component of the earth's magnetic field, of $0.3 \times 10^{-4} \mathrm{~Wb} / \mathrm{m}^{2}$. The value of the induced emf in wire is :
Correct Option: 1
Solution:
(1) Induced emf, $\varepsilon=\mathrm{B} v \ell$
$=0.3 \times 10^{-4} \times 5 \times 10$
$=1.5 \times 10^{-3} \mathrm{~V}$