Question

A metallic rod of length 20 cm is placed in North-South direction and is moved at a constant speed of 20 m/s towards East. The horizontal component of the Earth's magnetic field at that place is 4 × 10³ T and the angle of dip is 45°. The emf induced in the rod is ______ mV.

Options

• 15

• 16

• 17

• 18

Answer 1

A metallic rod of length 20 cm is placed in North-South direction and is moved at a constant speed of 20 m/s towards East. The horizontal component of the Earth's magnetic field at that place is 4 × 10³ T and the angle of dip is 45°. The emf induced in the rod is 16 mV.

Explanation:

The magnetic field's vertical component will be cut perpendicularly by the moving rod.

So, e = B_v l V

= B_H × l V   [∵ Dip = 45° ⇒ B_v = B_H]

= 4 × 10^-3 × 0.2 × 20 

= 16 × 10^-3 V