A diode valve is connected to a battery and a load resistance. The filament is heated so that a constant current is obtained in the circuit. As the cathode continuously emits electrons, does it get more and more positively charged?
The important thing to note in this question is that diode’s cathode is connected to battery’s negative terminal. When filament is heated it will continuously emit electrons from it but battery’s negative terminal will also provide electrons which makes the diode electrically neutral in nature