The grid in a triode valve is used

When the plate voltage in a diode valve is increased from $100 \, V$ to $150 \, V$, the plate current increases from $7.5 \, mA$ to $12 \, mA$. The dynamic plate resistance will be.... $k \, \Omega$.

In the grid circuit of a triode, an input voltage $E = 2\sqrt{2} \cos \omega t$ is applied. If the amplification factor $\mu = 14$ and the plate resistance $r_p = 10 \text{ k}\Omega$, find the $r.m.s.$ current flowing through the load resistance $R_L = 12 \text{ k}\Omega$ in $\text{mA}$.

The plate characteristic curve of a diode in the space charge limited region is as shown in the figure. The slope of the curve at point $P$ is $5.0 \, mA/V$. The static plate resistance of the diode will be ...... $\Omega$.

The amplification factor of a triode is $10$. When the plate potential is $200 \, V$ and the grid potential is $-4 \, V$,a plate current of $4 \, mA$ is observed. If the plate potential is changed to $160 \, V$ and the grid potential is kept at $-7 \, V$,then the plate current will be.....$mA$.

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