Question

A conducting loop has an area of 0.065 m2 and is positioned such that a uniform magnetic field is perpendicular to the plane of the loop. When the magnitude of the magnetic field decreases to 0.30 T in 0.087 s, the average induced emf in the loop is 1.2 V. What is the initial value of the magnetic field?

Answer 1

Answer:

initial magnetic field  1.306 T

Explanation:

We have given area of the conducting loop $A=0.065m^2$

Emf induced = 1.2 volt

Initial magnetic field B = 0.3 T

Time dt = 0.087 sec

We know that induced emf is given by $e=\frac{d\Phi }{dt}=-A\frac{db}{dt}$

$1.2=0.065\times \frac{db}{0.087}$

$db=1.606T$

So initial magnetic field = 1.606-0.3= 1.306 T