Question

A uniform but time-varying magnetic field B(t) exists in a circular region of radius a and is directed into the plane of the paper, as shown. The magnitude of the induced electric field at point P at a distance r from the centre of the circular region

A. is zero
B. decreases as 1/r
C. increases as r
D. decreases as` 1/r^(2)`

Answer 1

(b) Usin, `oint E. dl = -(d phi)/(dt)`
`rArr E(2pir) = " constant " rArr E alpha (1)/(r)`