induced E

are d four options correct............ i think its proportional to 1/r³

yes dear :) absolutely corect options... no typo :)

then is it option 3) ?????????????

well, for this , there must be a condition on B,
it must only be a function of time.

can any one explain it plz.......

yes it is a function of time (sorry not mentioned)

anyone plz??????????????????????????????????????????

dΦ = ∫E.dl
dt

as E is same for circular region passing over P..

so
dΦ = E.∫dl
dt

AdB/dt=E2Ï€R

E=A(dB/dt)
2Ï€R

so E α 1/r