Question

A 10-meter wire is kept in east-west direction. It is falling down with a speed of 5.0 meter/second, perpendicular to the horizontal component of earth's magnetic field of 0.30 × 10⁻⁴ weber/meter². The momentary potential difference induced between the ends of the wire will be:

Options

• 0.0015 V

• 0.015 V

• 0.15 V

• 1.5 V

Answer 1

0.0015 V

Explanation:

If a wire, ℓ meter in length, moves perpendicular to a magnetic field of B weber/meter² with a velocity of v meter/second, then the e.m.f. induced in the wire is given by

V = Bvℓ volt

Here, B = 0.30 × 10⁻⁴  weber/meter²,

v = 5.0 meter/second and ℓ = 10 meter

∴ B = 0.30 × 10⁻⁴ × 5.0 × 10 = 0.0015 volt