Correct Answer - A
Here, area, `A=10xx5=50cm^(2)=50xx10^(-4)m^(2)`
`(dB)/(dt)=0.2Ts^(-1)rArrR=2Omega`
`therefore" emf, e"=(dphi)/(dt)=A.(dB)/(dt)=50xx10^(-4)xx0.02=10^(-4)V`
Power dissipated in the form of heat
`=(e^(2))/(R)=(10^(-4)xx10^(-4))/(2)=0.5xx10^(-8)W=5xx10^(-9)W=5nW`