Question

When a triode valve is used as an amplifier the phase difference between input and output voltages is

• A. zero
• B. $\frac{\pi}{4}$
• C. $\frac{\pi}{2}$
• D. $\pi$

Answer 1

Answer: (D)

$\pi$

Answer 2

Triode valve consists of a cathode, grid and anode. When current is passed in the filament by connecting it to a battery, the filament is heated and it heats up the cathode, so electrons start emitting from the cathode. Anode plate is connected to the positive terminal of a battery. Thus, anode is positive with respect to cathode, electrons being negatively charged get attracted towards anode and a continuous plate current flows. when both grid and anode are positive maximum plate current flows.