A conducing circular loop is placed in a uniform magnetic field of indution `B` tesla with its plane normal to the field. Now, radius of the loop starts shrinking at the rate `(dr//dt)`. Then the induced e.m.f. at the instant when the radius is `r` is:

Options

A. `pirB((dr)/(dt))`
B. `2pirB((dr)/(dt))`
C. `pir^(2)((dB)/(dt))`
D. `B(pir^(2))/(2)(dr)/(dt)`

Answer

C

Explanation

`CuS+KCN("excess")hArr underset("colourless", "diamagnetic")(K_(3
)[Cu(CN)_(4)])`