The amplification factor of a triode valve is $15$. If the grid voltage is changed by $0.3 \,V$,what is the change in plate voltage required to keep the plate current constant (in $V$)?

The mutual characteristic of a triode is represented by which of the following graphs?

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

The slopes of the anode and mutual characteristics of a triode are $0.02 \, mA/V$ and $1 \, mA/V$ respectively. What is the amplification factor of the valve?

$A$ triode has a plate resistance of $10 \, k\Omega$ and an amplification factor of $24$. If the input signal voltage is $0.4 \, V$ $(r.m.s.)$ and the load resistance is $10 \, k\Omega$,then the output voltage $(r.m.s.)$ is ...... $V$.

If ${R_p} = 7 \text{ k}\Omega$ and ${g_m} = 2.5 \text{ millimho}$, then on increasing the plate voltage by $50 \text{ V}$, how much must the grid voltage be changed so that the plate current remains the same? (in $V$)