The amplification factors of a triode valve depends on:

Correct the following sentence:

When the triode is used as an amplifier the phase difference between input signal voltage and output is $\pi /2$.

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$

On which one of the following factors, the amplification factors of a triode valve depends?

a) Temperature of the cathode b) Temperature of anode c) Supplied plate voltage d) relative positions of cathode, grid and anode.

On which one of the following factors, the amplification factors of a triode valve depends?