Which among the following graphs explains the photoelectric effect?

Options

A.
B.
C.
D.

Explanation

To determine which graph explains the photoelectric effect, we will analyze the relationship between the kinetic energy of emitted electrons and the frequency of the incident light.

### Step-by-Step Solution:

1. **Understanding the Photoelectric Effect**:
The photoelectric effect occurs when light shines on a material and causes the emission of electrons. The energy of the incident photons is given by the equation:
\[ E = h \nu \]
where \( E \) is the energy of the photon, \( h \) is Planck's constant, and \( \nu \) is the frequency of the light.

2. **Kinetic Energy of Emitted Electrons**:
The kinetic energy (KE) of the emitted electrons can be expressed as:
\[ KE = h \nu - h \nu_0 \]
where \( \nu_0 \) is the threshold frequency, the minimum frequency required to emit electrons from the material.

3. **Rearranging the Equation**:
We can rearrange the equation for kinetic energy:
\[ KE = h (\nu - \nu_0) \]
This shows that the kinetic energy is directly proportional to the frequency of the incident light minus the threshold frequency.

4. **Graphical Representation**:
- On the graph, we can plot the kinetic energy (KE) on the x-axis and the frequency (\( \nu \)) on the y-axis.
- The intercept on the y-axis (when KE = 0) occurs at \( \nu = \nu_0 \).
- The slope of the line will be \( h \), which is a constant.

5. **Identifying the Correct Graph**:
- The correct graph will start at the threshold frequency (\( \nu_0 \)) on the x-axis and will have a positive slope.
- This means that the graph should not intersect the x-axis (KE cannot be negative) and should be above the origin.

6. **Conclusion**:
Based on the analysis, the correct graph that explains the photoelectric effect is the one that starts from the x-axis at \( \nu_0 \) and rises linearly, which corresponds to option B.

### Final Answer:
The graph that explains the photoelectric effect is option B.