Question

A 10 m long copper wire while remaining in the east-west horizontal direction is falling down with a constant speed of 5.0 m/s. If the horizontal component of the earth's magnetic field $0.30\times {10}^{-4}Werber/m^2$.

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

• A. $0.15volts$
• B. $1.5volts$
• C. $0.15milivolts$
• D. $1.5milivolts$

Answer 1

The correct option is D $1.5milivolts$

Here,

Length of the wire, $l=10$m

Speed, $V=5m/s$

Earth's magnetic field , $B=0.30\times {10}^{-4}Wb{m}^{-2}$

We know,

Instantaneous value of e.m.f induced in the wire ,

$e=BIV$

$\begin{array}{c}=0.30\times {10}^{-4}\times 10\times 5.0\\ =1.5\times {10}^{-3}V\end{array}$