Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Electric Current through Gases
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Electric Current through Gases
As a result of the space charge in a diode valve,
As a result of the space charge in a diode valve,
Options
- Athe emission rate of thermions increases
- Bthe saturation current increases
- Cthe plate current decreases
- Dthe plate voltage increases
Correct answer
C. the plate current decreases
Step-by-step solution
In a diode valve, the space charge is the accumulation of emitted electrons in the region between the cathode and the anode. Since electrons are negatively charged, this electron cloud exerts a repulsive force on the newly emitted thermions from the cathode.
Due to this repulsion, some of the emitted electrons are pushed back towards the cathode and are unable to reach the anode. Consequently, the net flow of electrons to the plate is reduced, which means the plate current decreases.
Due to this repulsion, some of the emitted electrons are pushed back towards the cathode and are unable to reach the anode. Consequently, the net flow of electrons to the plate is reduced, which means the plate current decreases.