A circular coil of radius 2.00 cm has 50 turns. A uniform magnetic field B= 0.200 T exists in the space is a direction parallel to the axis of the loop. The coil is now rotated about a diameter through an angle of `60.0^@`. The operation takes 0.100 s. (a) find the average emf induced in the coil. (b) if the coil is a closed one(with the two ends joined together) and has a resistance of `4.00 Omega`. calculate the net charge crossing a cross- section of the wire of the coil.

Explanation

`A=2cm^(2)=2xx10^(-4)m^(2)` , `B=0.2T` , `N=50`
`t_(1)=0` , `phi_(1)=NBAcos0=NBA`
`t_(2)=0.1sec` , `phi_(2)=NBAcos60^(@)=(NBA)/(2)`
(a) `|bar(e)|=(Deltaphi)/(Deltat)=(NBA//2)/(Deltat)`
`=(5-0xx0.2xx2xx10^(-4))/(2xx0.1)=10^(-2)V`
(b) `Deltaq=(Deltaphi)/(R)=(10^(-3))/(4)=2.5xx10^(-4)C`