A loop of wire of radius a = 50. mm has an electrical resistance R = 0.039 . The

Question

A loop of wire of radius a = 50. mm has an electrical resistance R = 0.039 . The loop is initially inside a uniform magnetic field of magnitude B0 = 1.9 T parallel to the loop's axis. The magnetic field is then reduced slowly at a constant rate, which induces a current I = 0.20 A in the loop. How long does it take for the magnitude of the uniform magnetic field to drop from 1.9 T to zero?

Find the time t it takes the magnetic field to drop to zero.

Express your answer in seconds using two significant figures.

Explanation / Answer

Here,

a = 50 mm = 0.050 m

R = 0.039 Ohm

Bo = 1.9 T

I = 0.20 A

let the time taken is t

Now , for the induced current in the loop

Induced current = rate of change of magnetic flux/Resistance of the loop

0.20 = pi * 0.050^2 * (1.90 - 0)/(t * 0.039)

solving for t

t = 1.913 s

the time interval for the change in magnetic field must be 1.913 s

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.