A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is

Question

A conducting circular loop is placed in a uniform magnetic field 0.04 T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2 mm/s. The induced emf in the loop when the radius is 2 cm is (A) 4.8πμ V (B) 0.8πμ V (C) 1.6πμ V (D) 3.2πμ V

Tardigrade Admin · Accepted Answer

e =( d φ/ dt )=( d / dt )( B π r 2) =2 π rB ( dr / dt ) =2 × π × 2 × 10-2 × 4 × 10-2 × 2 × 10-3 =3.2 × 10-6 π Vol =3.2 π μ V

Q. A conducting circular loop is placed in a uniform magnetic field $0.04 T$ with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at $2 mm / s .$ The induced emf in the loop when the radius is $2 c m$ is

$4.8 π μ V$

$0.8 π μ V$

$1.6 π μ V$

$3.2 π μ V$

$e = \frac{d ϕ}{d t} = \frac{d}{d t} (B π r^{2})$
$= 2 π r B \frac{d r}{d t}$
$= 2 \times π \times 2 \times 1 0^{- 2} \times 4 \times 1 0^{- 2} \times 2 \times 1 0^{- 3}$
$= 3.2 \times 1 0^{- 6} πV o l = 3.2 π μ V$

Q. A conducting circular loop is placed in a uniform magnetic field 0.04T with its plane perpendicular to the magnetic field. The radius of the loop starts shrinking at 2mm/s. The induced emf in the loop when the radius is 2cm is

4.8πμV

0.8πμV

1.6πμV

3.2πμV