Assertion : Unlike electric force and gravitational forces, nuclear force has limited range.
Reason : Nuclear force do not obey inverse square law.

Options

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

Answer

To analyze the given assertion and reason, let's break down the concepts step by step.

### Step 1: Understanding the Assertion
The assertion states that "Unlike electric force and gravitational forces, nuclear force has limited range."

- **Explanation**: The nuclear force, which includes the strong nuclear force and weak nuclear force, operates over a very short distance, typically on the order of femtometers (10^-15 meters). In contrast, both electric and gravitational forces have an infinite range, meaning they can act over any distance, albeit their strength diminishes with distance.

### Step 2: Understanding the Reason
The reason states that "Nuclear forces do not obey inverse square law."

- **Explanation**: The inverse square law applies to both gravitational and electric forces, meaning that the force between two objects decreases with the square of the distance between them. However, nuclear forces do not follow this law; they are effective only at very short ranges and their strength does not diminish according to the inverse square law.

### Step 3: Evaluating the Relationship
Now we need to evaluate whether the reason provided supports the assertion.

- **Analysis**: While both the assertion and the reason are true statements, the reason does not explain why the nuclear force has a limited range. The limited range is a characteristic of the nuclear force itself, while the reason discusses the nature of how the force behaves with distance, which is a separate aspect.

### Conclusion
- **Final Answer**: Both the assertion and reason are true, but the reason is not a valid explanation for the assertion. Therefore, the correct conclusion is that the assertion is true, the reason is true, but the reason does not explain the assertion.