A 18.5-cm-diameter loop of wire is initially oriented perpendicular to a 1.3-T magnetic field. The loop is rotated so that its plane is parallel to the field direction in 0.18 s . What is the average induced emf in the loop? Express your answer to two significant figures and include the appropriate units.

0.2v

Explanation:

Data given,

Diameter=18.5cm

Hence we can calculate the radius as D/2=18.5/2=9.25cm

radius=9.25cm/100=0.0925m

The area is calculated as

magnetic field, B=1.3T

time,t=0.18s

The flux is expressed as

since the loop is parallel, the angle is 0

Hence we can calculate the flux as

to determine the emf induced in the loop, we use Faraday law

Note the voltage is not negative but the negative sign shows the current flows in other to oppose the flux

need to see circuit to get time constant