A circular coil of radius 0.5 m and resistance 3.14 `Omega` is placed in a magneti induction with its plane perpendicular to the field. The rate of charnge of magnetic induction so as to produce a current of 50 mA in a coil is

Options

A. 0.2 Wb/`m^(2)s`
B. 0.2 T/s
C. 0.02 T/s
D. both 'a' and 'b'

Answer

D

Explanation

`e=A(dB)/(dt)`
`therefore (dB)/(dt)=(e)/(A)=(IR)/(A)=(IR)/(pir^(2))=(50xx10^(-3)xx3.14)/(3.14xx0.5xx0.5)`
`=0.2T//s or 0.2 Wb//m^(2)s`