The voltage gain of a triode depends upon

In the circuit of a triode valve,there is no change in the plate current when the plate potential is increased from $200 \ V$ to $220 \ V$ and the grid potential is decreased from $-0.5 \ V$ to $-1.3 \ V$. The amplification factor of this valve is

In a triode,${g_m} = 2 \times 10^{-3} \, \Omega^{-1}$,$\mu = 42$,and the resistance load $R_L = 50 \, \text{k}\Omega$. The voltage amplification obtained from this triode will be:

The plate resistance of two triode valves is $2 \, k\Omega$ and $4 \, k\Omega$. The amplification factor of each valve is $40$. The ratio of voltage amplification,when used with a $4 \, k\Omega$ load resistance,will be:

The grid in a triode valve is used

For a given plate-voltage,the plate current in a triode is maximum when the potential of