Physics - Modern Physics Question with Solution | TestHub
An experimental setup of verification of photoelectric effect is shown in figure. The voltage across the electrodes is measured with the help of an ideal voltmeter, which can be varied by moving jockey 'J' on the potentiometer wire. The battery used in the potentiometer circuit is of 20 V and its internal resistance is 2 Ω. The resistance of 100 cm long potentiometer wire is 8 Ω. The photocurrent is measured with the help of an ideal ammeter. Two plates of potassium oxide of area 50 cm² at separation 0.5 mm are used in the vacuum tube. Photocurrent in the circuit is very small, so the potentiometer circuit can be treated as an independent circuit.
When a light falls on the anode plate, the ammeter reading remains zero till jockey is moved from the end P to the middle point of the wire PQ. There after, the deflection is recorded in the ammeter. The maximum kinetic energy (in eV) of the emitted electron is :-
Answer:
Solution:
Ammeter reads zero till the jockey reaches the midpoint, so stopping potential
Answer 8.00
