Question

For given experimental setup, to increase photocurrent, which of the following ways can be used

• A. Source is brought near to window
• B. A $60\text{W}$ bulb is replaced with $100\text{W}$ bulb
• C. Frequency of radiation is increased
• D. Both $\left(a\right)\text{\&}\left(b\right)$

Answer 1

The correct option is D Both $\left(a\right)\text{\&}\left(b\right)$

If the source is brought closer to the window, intensity increases, thus, increasing number of photons, which increases the emission of number of free electrons from the cathode plate.

So, emitting more number of free electrons per second, increases the photo current.

Similarly, replacing the $60\text{W}$ bulb with a $100\text{W}$ bulb, increases the intensity of the source and thus increasing the photocurrent.

Increasing the frequency of the source, increases the energy of the incident photon and does not affect the photo current.

Hence, option $\left(\text{D}\right)$ is the correct answer.

Why this question? This question tests dependence of photocurrent on Intensity & frequency with the help of experimental set up.