Choose the correct statements regarding the phenomena of photoelectric effect

Options

A. Photoelectric effect was explained by Einstein considering wave nature of light
B. If intensity of radiations incident on photosensitive material is increases, stopping potential increases
C. Work function of gold is about 5.1 eV
D. Slope of a graph between incident frequency (greater than threshold frequency ) verses stopping potentials is independent of metal

Answer

To solve the question regarding the phenomena of the photoelectric effect, we will analyze each statement provided and determine whether it is correct or not based on the principles of the photoelectric effect.

### Step 1: Understanding the Photoelectric Effect
The photoelectric effect is a phenomenon where electrons are emitted from a material (usually a metal) when it is exposed to light of sufficient frequency. This effect was explained by Albert Einstein, who proposed that light can be thought of as consisting of particles called photons.

### Step 2: Evaluating the Statements

1. **Statement 1: "Photoelectric effect was explained by Einstein considering wave nature of light."**
- **Evaluation**: This statement is incorrect. Einstein explained the photoelectric effect using the particle nature of light. He proposed that light consists of discrete packets of energy (photons), and the energy of each photon is proportional to its frequency. The wave nature of light does not account for the threshold frequency concept, which is crucial in the photoelectric effect.

2. **Statement 2: "If intensity of radiation incident on the photosensitive metal increases, the stopping potential increases."**
- **Evaluation**: This statement is also incorrect. The stopping potential depends on the maximum kinetic energy of the emitted electrons, which is determined by the frequency of the incident radiation, not its intensity. Increasing the intensity increases the number of photons (and thus the number of emitted electrons if the frequency is above the threshold), but it does not affect the energy of individual photons.

3. **Statement 3: "Slope of graph between incident frequency greater than threshold frequency versus stopping potential is independent of metal."**
- **Evaluation**: This statement is correct. The slope of the graph that plots the stopping potential (V) against the frequency (f) of the incident light is given by \( \frac{h}{e} \), where \( h \) is Planck's constant and \( e \) is the charge of an electron. This slope is indeed independent of the type of metal used, as it only depends on fundamental constants.

### Conclusion
Based on the evaluations:
- Statement 1 is incorrect.
- Statement 2 is incorrect.
- Statement 3 is correct.

Thus, the correct statement regarding the phenomena of the photoelectric effect is the third one.