A coil of `40 Omega` resistance has `100` turns and radius `6 mm` us connected to ammeter of resistance of `160 ohms`. Coil is placed perpendicular to the magnetic field. When coil is taken out of the field, `32 mu C` charge flows through it. The intensity of magnetic field will be

Options

A. 6.55 T
B. 5.66 T
C. 2.55 T
D. 0.566 T

Answer

D

Explanation

We have, `Deltaq=-(N)/(R)Deltaphi and Deltaphi=DeltaB.A cos theta`
`therefore" "32xx10^(-6)=-(100)/(160+40)(0-B)xxpixx(6xx10^(-3))^(2)xxcos0^(@)`
`therefore` Intensity of magnetic field, `B=0.566T`