At stopping potential, the kinetic energy of emitted photoelectron is

Options

A. minimum
B. maximum
C. zero
D. cannot be predicted

Answer

To solve the question regarding the kinetic energy of emitted photoelectrons at stopping potential, we can follow these steps:

### Step 1: Understand the Concept of Stopping Potential
The stopping potential (V₀) is the potential difference needed to stop the most energetic photoelectrons emitted from a material when it is exposed to light. At this potential, the kinetic energy of the photoelectrons is completely converted into electrical potential energy.

### Step 2: Relate Stopping Potential to Kinetic Energy
The maximum kinetic energy (K_max) of the emitted photoelectrons can be expressed in terms of the stopping potential:
\[ K_{max} = eV_0 \]
where:
- \( K_{max} \) is the maximum kinetic energy of the photoelectrons,
- \( e \) is the charge of the electron (approximately \( 1.6 \times 10^{-19} \) coulombs),
- \( V_0 \) is the stopping potential.

### Step 3: Analyze the Kinetic Energy at Stopping Potential
At the stopping potential, the kinetic energy of the emitted photoelectrons is at its maximum. Therefore, we can conclude that:
\[ K_{max} = eV_0 \]
This means that the kinetic energy of the photoelectrons at the stopping potential is equal to the energy imparted to them by the incident photons minus the work function of the material.

### Step 4: Conclusion
Thus, the kinetic energy of the emitted photoelectrons at the stopping potential is equal to the maximum kinetic energy, which is given by the equation:
\[ K_{max} = eV_0 \]

### Final Answer
The kinetic energy of emitted photoelectrons at stopping potential is \( K_{max} = eV_0 \).

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