Question

A conducting wire of length 2500 m is kept in east-west direction, at a height of 10 m from the ground. If it falls freely on the ground then the current induced in the wire is (Resistance of wire $= 25\sqrt{2} \;\Omega$, acceleration due to gravity $g=10\text{ m/s}^2$, $B_H=2\times10^{-5}\text{ T}$)

• A. 0.2 A
• B. 0.02 A
• C. 0.01 A
• D. 2 A

Hint:

Logic Tip: The orientation of the wire is critical. A wire falling horizontally while oriented East-West cuts the North-South magnetic field lines of the Earth, generating max EMF. If the wire were oriented North-South while falling, it would be parallel to the magnetic field lines, cutting nothing, and the induced EMF would be zero!

Answer 1

The Correct Option is B