Question

Question 1: A 13.7 cm diameter loop of wire is initially oriented perpendicular to a 1.9 T magnetic field. The loop is rotated so that its plane is parallel to the field direction in 0.33 s .

Part A: What is the average induced emf in the loop?

Question 2: A 7.4 cm diameter circular loop of wire is in a 0.71 T magnetic field. The loop is removed from the field in 0.28 s . Assume that the loop is perpendicular to the magnetic field.

Part A: What is the average induced emf?

Answer 1

Question 1:

Induced Emf is given by,

E=-N*  

N is the number of turns in the coil

is the magnetic flux in Tm2

is the time taken for the flux to change.

Magnetic flux is given by:

B is the magnetic field

A is the Area.

Given:

B=1.9T, A= *(.137/2)2 = 0.014733m2

= 1.9 * 0.014733 * Cos 0 = 0.027994 Wb

Induced EMF is given by:

E=-N*  

= - 1 * (0.027994/0.33) = - 0.08483V

The Induced Emf is 0.08483V

Question 2:

Induced Emf is given by,

E=-N*  

N is the number of turns in the coil

is the magnetic flux in Tm2

is the time taken for the flux to change.

Magnetic flux is given by:

B is the magnetic field

A is the Area.

Given:

B=0.71T, A= *(0.074/2)2 = 0.004298m2

= 0.71 * 0.004298 * Cos 0 = 0.00305 Wb

Induced EMF is given by:

E=-N*  

= - 1 * (0.00305/0.28) = - 0.0109V

The Induced Emf is 0.0109V