Which of the following components acts as a complete electronic circuit?

The time variations of signals $A, B$ and $C$ are shown below. Choose the correct statement.

Three amplifiers with voltage gains $10, 20$ and $30$ are connected in series. If the input signal has a peak value of $1 mV$, then the peak value of the output voltage is (in $\,V$)

Given below are two statements:
Statement $I$: Photovoltaic devices can convert optical radiation into electricity.
Statement $II$: Zener diode is designed to operate under reverse bias in the breakdown region.
In the light of the above statements,choose the most appropriate answer from the options given below:

The energy of a photon of sodium light $(\lambda = 589 \text{ nm})$ is equal to the band gap of a semiconductor. Find the minimum energy $E$ in $eV$ required to create an electron-hole pair.

The frequency response curve of an $RC$ coupled amplifier is shown in the figure. The bandwidth of the amplifier will be