When forward bias is applied to a p-n junction, then the potential barrier and the width of the depletion region respectively.

In common emitter configuration, $\beta, \mathrm{R}_{\mathrm{L}}$ and r are the a.c. current gain, load resistance and the input resistance of a transistor respectively. The voltage and power gain respectively are

The order of (a) transformer (b) diode rectifier (c) filter (d) voltage regulator in a block diagram of simple rectifier circuit is as

(a) b, d, c, a

(b) a, c, d, b

(c) a, b, c, d

(d) d, c, a, b