Assertion: A metal rod is moved perpendicular to the length of rod and uniform magnetic field exits perpendicular to the plane of motion of rod. Electric field is generated along the length of the rod.
Reason: When metallic object moves inside magnetic field then free electrons experience force and are moved in the direction of force. Due to redistribution of electrons, electric field is created in the metal.

Options

A. If both assertion and reason are correct and reason is correct explanation of the assertion
B. If both assertion and reason are correct but reason is not correct explanation of the assertion
C. If assertion is correct but reason is incorrect.
D. If assertion is incorrect but reason is correct.

Answer

To analyze the given assertion and reason, we can break down the explanation into clear steps:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- We have a metal rod that is moving perpendicular to its length.
- There is a uniform magnetic field that is also perpendicular to the plane of motion of the rod.

2. **Direction of Motion and Magnetic Field**:
- Assume the rod is moving to the right (along the x-axis).
- Let the magnetic field be directed downwards (along the negative y-axis).

3. **Lorentz Force on Electrons**:
- As the metal rod moves through the magnetic field, the free electrons in the rod experience a magnetic force due to their motion in the magnetic field.
- According to the Lorentz force law, the force \( F \) on a charge \( q \) moving with velocity \( v \) in a magnetic field \( B \) is given by:
\[ F = q(\mathbf{v} \times \mathbf{B}) \]
- In this case, the direction of the force acting on the electrons can be determined using the right-hand rule.

4. **Redistribution of Electrons**:
- The electrons will experience a force that causes them to move to one side of the rod (let's say to the left side).
- This movement of electrons results in a redistribution of charge within the rod.

5. **Creation of Electric Field**:
- The accumulation of negative charge on one side of the rod leads to a potential difference along the length of the rod.
- This potential difference creates an electric field along the length of the rod.

6. **Conclusion**:
- Therefore, the assertion that an electric field is generated along the length of the rod when it moves in a magnetic field is correct.
- The reason provided explains that the movement of the electrons under the influence of the magnetic force leads to this electric field due to the redistribution of charge.

### Final Statement:
Both the assertion and reason are correct. The motion of the rod in the magnetic field induces an electric field along its length due to the movement of free electrons.

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