In the experiment on photoelectric effect using light having frequency greater than the threshold frequency, the photocurrent will certainly increase whena)Anode voltage is incrasedb)Area of cathode surface is increasedc)Intensity of incident light is increasedd)Distance between anode and cathode is increased.Correct answer is option 'B,C'. Can you explain this answer?

Question

Answer

If light of certain frequency, greater than the threshold frequency, is incident of the metal surface the photoelectric current obtained is directly proportional to the number of photo-electrons emitted. On increasing the frequency of incident light (or) by increasing the anode potential the speed of photo-electrons emitted changes but they have no effect on the number of electrons emitted. But by increasing the intensity of the incident light more photo-electrons will be emitted and thereby increasing the photoelectric current.
Also, if we increase the area on which the light is incident we can get more electrons emitted which increases the photoelectric current.

Answer

If light of certain frequency, greater than the threshold frequency, is incident of the metal surface the photoelectric current obtained is directly proportional to the number of photo-electrons emitted. On increasing the frequency of incident light (or) by increasing the anode potential the speed of photo-electrons emitted changes but they have no effect on the number of electrons emitted. But by increasing the intensity of the incident light more photo-electrons will be emitted and thereby increasing the photoelectric current.
Also, if we increase the area on which the light is incident we can get more electrons emitted which increases the photoelectric current.

Answer

Explanation:

The photoelectric effect is a phenomenon where electrons are emitted from a metal surface when light falls on it. For photoelectrons to be emitted, the frequency of the incident light should be greater than the threshold frequency of the metal. The photocurrent is the current that flows in the circuit due to the emission of electrons from the metal surface.

Effect of Anode Voltage:
The anode voltage is the potential difference between the anode and cathode in the circuit. Increasing the anode voltage will not increase the number of photoelectrons emitted from the metal surface. Hence, the photocurrent will not increase when the anode voltage is increased.

Effect of Distance between Anode and Cathode:
The distance between the anode and cathode in the circuit has no effect on the number of photoelectrons emitted from the metal surface. Hence, the photocurrent will not increase when the distance between the anode and cathode is increased.

Effect of Area of Cathode Surface:
Increasing the area of the cathode surface will increase the number of photoelectrons emitted from the metal surface. This is because a larger area of the metal surface is exposed to the incident light, which results in more photoelectrons being emitted. Hence, the photocurrent will increase when the area of the cathode surface is increased.

Effect of Intensity of Incident Light:
Increasing the intensity of the incident light will increase the number of photons incident on the metal surface. This will result in the emission of more photoelectrons from the metal surface. Hence, the photocurrent will increase when the intensity of the incident light is increased.

Therefore, the correct options are B and C, i.e., the photocurrent will certainly increase when the area of the cathode surface is increased and the intensity of the incident light is increased.

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