In photoelectric effect,

Options

A. In photoelectric current is directly proportional to the intensity of incident light.
B. `K.E._(max)` of ejected electrons is dependent on intensity of radiations.
C. there is no time lag between the incidence of photons and ejection of electrons
D. All of these are correct.

Explanation

### Step-by-Step Solution:

1. **Understanding the Photoelectric Effect**: The photoelectric effect refers to the phenomenon where electrons are ejected from a material (usually a metal) when it is exposed to light (or electromagnetic radiation) of sufficient frequency.

2. **Current and Intensity Relationship**: The current produced in the photoelectric effect is directly proportional to the intensity of the incident light. This is because:
- Increasing the intensity of light means increasing the number of photons hitting the surface of the metal.
- More photons lead to more ejected electrons, which in turn increases the current.

Therefore, we can conclude that **Current ∝ Intensity**.

3. **Kinetic Energy of Ejected Electrons**: The maximum kinetic energy (K.E.) of the ejected electrons is dependent on the frequency of the incident light, not on its intensity. According to Einstein's photoelectric equation:
\[ K.E. = hf - \phi \]
where \(hf\) is the energy of the incident photon (with \(h\) being Planck's constant and \(f\) the frequency) and \(\phi\) is the work function of the metal.
- If the frequency increases, the kinetic energy increases.
- If the frequency decreases, the kinetic energy decreases.
- Thus, the kinetic energy is independent of the intensity of the radiation.

4. **Time Lag in Electron Ejection**: There is no time lag between the incidence of a photon and the ejection of an electron. This means that the process is instantaneous:
- When a photon with sufficient energy strikes the metal, the electron is emitted immediately without any delay.

5. **Conclusion**:
- The first statement about current being directly proportional to intensity is correct.
- The second statement about maximum kinetic energy depending on intensity is incorrect; it depends on frequency.
- The third statement about no time lag in the ejection process is correct.

### Final Summary:
- **Correct Statements**:
1. Current is directly proportional to the intensity of incident light.
2. There is no time lag between the incident photon and ejection of the electron.
- **Incorrect Statement**:
1. Maximum kinetic energy of ejected electrons depends on the intensity of radiation.