A resistance R $\left(\Omega \right)$ and a capacitor C (F) is connected with a metal wire to form a loop and this is placed in a magnetic field that points vertically into the loop and is decreasing at a constant rate $\frac{dB}{dt}=-k$.

Choose the correct statements.

(a) Induced emf $=-\frac{d}{dt}NBA=-\pi a^2\left(\frac{d}{dt}B\right)=\pi a^{2}k$

(b) Charge stored, $Q=CE=C\pi a^{2}k$

(c) B points into plane of paper and is decreasing so induced emf also produces a field that points into the paper.

$\therefore$Current flows clockwise and so upper plate is positive.

(d) Changing B induces E and this pushes on charges in the wire.