The emf induced in a rotating disc in a magnetic field is given by the formula:

ε = 1/2 * B * ω * r^2

where:
B is the magnetic field strength,
ω is the angular velocity, and
r is the radius of the disc.

Given:
B = 0.1 T,
ω = 20 revolutions per second = 20 * 2π rad/s (since 1 revolution = 2π rad), and
r = 0.1 m,

we can substitute these values into the formula:

ε = 1/2 * 0.1 T * (20 * 2π rad/s) * (0.1 m)^2
ε = 0.02π V

So, the emf induced across the radius of the disc is 0.02π volts.

Question

The emf induced in a rotating disc in a magnetic field is given by the formula:

ε = 1/2 * B * ω * r^2

where:
B is the magnetic field strength,
ω is the angular velocity, and
r is the radius of the disc.

Given:
B = 0.1 T,
ω = 20 revolutions per second = 20 * 2π rad/s (since 1 revolution = 2π rad), and
r = 0.1 m,

we can substitute these values into the formula:

ε = 1/2 * 0.1 T * (20 * 2π rad/s) * (0.1 m)^2
ε = 0.02π V

So, the emf induced across the radius of the disc is 0.02π volts.

Knowee AI · Accepted Answer

The emf induced in a rotating disc in a magnetic field is given by the formula:

ε = 1/2 * B * ω * r^2

where:
B is the magnetic field strength,
ω is the angular velocity, and
r is the radius of the disc.

Given:
B = 0.1 T,
ω = 20 revolutions per second = 20 * 2π rad/s (since 1 revolution = 2π rad), and
r = 0.1 m,

we can substitute these values into the formula:

ε = 1/2 * 0.1 T * (20 * 2π rad/s) * (0.1 m)^2
ε = 0.02π V

So, the emf induced across the radius of the disc is 0.02π volts.

A copper disc of the radius 0.1 m0.1 m is rotated about its centre with ω=20𝜔=20 revolutions per second in a uniform magnetic field of 0.1 T0.1 T with its plane perpendicular to the field. The emf induced across the radius of the disc is