A : An electron has negative charge by definition
R : Charge of a body depends on its velocity.

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1).
B. If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2).
C. If Assertion is true statement but Reason is false, then mark (3).
D. If both Assertion and Reason are false statements, then mark (4).

Answer

To analyze the given statements, we will break down the assertion and reason step by step.

### Step 1: Understanding the Assertion
- **Assertion (A)**: An electron has a negative charge by definition.
- **Explanation**: The electron is defined as a fundamental particle with a negative charge. This is a convention in physics, and it is universally accepted that the charge of an electron is -1.6 x 10^-19 coulombs. Therefore, this assertion is true.

### Step 2: Understanding the Reason
- **Reason (R)**: Charge of a body depends on its velocity.
- **Explanation**: The charge of a particle, such as an electron, does not change with its velocity. Charge is an intrinsic property of a particle and remains constant regardless of its motion. While relativistic effects can affect mass and energy, they do not affect the charge of a particle. Therefore, this reason is false.

### Step 3: Conclusion
- Since the assertion is true and the reason is false, we conclude that the correct interpretation of the statements is:
- Assertion (A) is true.
- Reason (R) is false.

### Final Answer
The correct answer is that the assertion is true, but the reason is false.

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