The region in the output voltage versus input voltage graph where a transistor can be used as an amplifier is

The voltage gain of a transistor in common emitter configuration is 160 . The resistances in base and collector sides of the circuit are $1 \mathrm{k} \Omega$ and $4 \mathrm{k} \Omega$ respectively. If the change in base current is $100 \mu \mathrm{~A}$, then the change in output current is

Normally a capacitor is connected across the output terminals of a rectifier to

A zener diode of zener voltage 30 V is connected in circuit as shown in the figure. The maximum current through the zener diode is