Question

ALLEN
A closed coil consists of 500 turns on a rectangular
frame of area 4.0 cm2 and has a resistance of
50 ohms. The coil is kept with its plane
perpendicular to a uniform magnetic field of
0.2 wb/m2, the amount of charge flowing through
the coil if it is turned over (rotated through 180°):-
(1) 1.6 x 10-3 C
(2) 16 x 10-3 C
(3) 0.16 x 10-3 C
(4) 160 x 10-3 C​

Answer 1

Answer:

Option 2) 16*10^-3 C.

Explanation:

Since, the coil is kept perpendicular in the direction of the magnetic field so the angle must be 0. So, flux will be  NBAcos0 which will be NBA. Then when the coil is turned 180 then the flux will be NBAcos180 which will be -NBA.

So, the difference between the flux will be -2NBA. The induced emf will be -2NBA/t. The induced current will be e/R which will be -2NBA/Rt. Now, we know that the charge will be i.t. Hence, the value of charge will be -2NBA/R on which substituting the values we will get 2*0.2*500*4*10^-4/50 which on solving we will get the value of charge to be 16*10^-3 C.