A metal disc of radius 200 cm is rotated at a constant angular speed of 60 rad s -1 in a plane at right angles to an external field of magnetic induction of 0.05 Wbm -2. Find the emf induced between the center and a point on the rim.

Question

A metal disc of radius 200 cm is rotated at a constant angular speed of 60 rad s -1 in a plane at right angles to an external field of magnetic induction of 0.05 Wbm -2. Find the emf induced between the center and a point on the rim. (A) 12 V (B) 8 V (C) 2 V (D) 6 V

Tardigrade Admin · Accepted Answer

e = BAv ⇒ B.A × (ω/2 π) ⇒ B × π R 2 × (ω/2 π) e=(1/2) B R2 ω ⇒ (1/2) × 0.05 ×(2)2 × 60=6 volt

Q. A metal disc of radius $200 c m$ is rotated at a constant angular speed of $60 r a d s^{- 1}$ in a plane at right angles to an external field of magnetic induction of $0.05 Wb m^{- 2}$ . Find the emf induced between the center and a point on the rim.

$12 V$

$8 V$

$2 V$

$6 V$

$e = B A v \Rightarrow B . A \times \frac{ω}{2 π}$
$\Rightarrow B \times π R^{2} \times \frac{ω}{2 π}$
$e = \frac{1}{2} B R^{2} ω$
$\Rightarrow \frac{1}{2} \times 0.05 \times (2)^{2} \times 60 = 6$ volt

Q. A metal disc of radius 200cm is rotated at a constant angular speed of 60rads−1 in a plane at right angles to an external field of magnetic induction of 0.05Wbm−2. Find the emf induced between the center and a point on the rim.

12V

8V

2V

6V