A physicist works in a laboratory where the magnetic field is `2T`. She wears a necklace enclosing area `0.01 m^(2)` in such a way that the plane of the necklace is normal to the field and is having a resistance `R=0.01Omega`. Because of power failure, the field decays to `1T` in time `10^(-3)` seconds.
The what is the total heat produced in her necklace?`(T=tesla)`

Options

A. 10 J
B. 20 J
C. 30 J
D. 40 J

Answer

A

Explanation

`H=(e^(2)t)/R`
`e=|(N(B_(2)-B_(1))Acostheta)/t|=|(1xx(1-2)xx0.01)/10^(-3)|=10V`
`thereforeH=((10)^(2)xx10^(-3))/0.01=10J`.