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 sta - Physics MCQ Physics | ExamTest.live

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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 $4.8 π μ V$
B $0.8 π μ V$
C $1.6 π μ V$
D $3.2 π μ V$

Solution & Step-by-step Explanation

Magnetic flux Φ = B A = B (π r^{2}) .Induced emf e = \frac{d Φ}{d t} : e = B \cdot π \cdot \frac{d ( r ^{2} )}{d t} = B \cdot π \cdot 2 r \frac{d r}{d t} Given: B = 0.04 T r = 2 cm = 0.02 m \frac{d r}{d t} = 2 mm/s = 0.002 m/s $ e = 0.04 \times π \times 2 \times 0.02 \times 0.002 $ e = 0.04 \times π \times 0.04 \times 0.002 = 3.2 π \times 1 0^{- 6} V = 3.2 π μ V

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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:

4.8 π μ V

0.8 π μ V

1.6 π μ V

3.2 π μ V

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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:

Solution & Step-by-step Explanation

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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:

Solution & Step-by-step Explanation

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Discussion

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: