Physics

Problem

Which one of the following expressions gives the instantaneous emf

ε

induced in a secondary coil when the current

I

in a nearby primary coil changes at a rate

\frac{dI}{dt}

? a)

ε = -N\dfrac{dΦ}{dt}

ε = +M\dfrac{dI}{dt}

ε = -M\dfrac{dI}{dt}

ε = -L\dfrac{dI}{dt}