$A$ serious drawback of semiconductor devices is:

Which of the following does not vary with plate or grid voltages in a vacuum triode?

In an amplifier,the load resistance ${R_L}$ is equal to the plate resistance ${r_p}$. The voltage amplification is equal to:

$A$ triode whose mutual conductance is $2.5 \text{ mA/V}$ and anode resistance is $20 \text{ k}\Omega$,is used as an amplifier whose amplification factor is $10$. The load resistance connected in the plate circuit will be.....$\text{k}\Omega$.

The current conduction in a discharge tube is due to

$14 \times 10^{15}$ electrons reach the anode per second. If the power consumed is $448 \text{ mW}$,then the plate (anode) voltage is .... $V$.