Assertion : Angle of repose is equal to angle of limiting friction. Reason : When the body is just at the point of motion, the force of friction in this stage is called as limiting friction.

Options

A. Both Assertion and Reason are correct, Reason is the coreect expianation of Assertion
B. Bioth Assertion and Reason are Correct but Reason is not the correct expalnation of Assertion
C. Assetion is correct and Reason is incorrect
D. Assertion is incorrect and Reason is correct

Answer

To solve the given question, we need to analyze the assertion and the reason provided.

### Step 1: Understand the Assertion
The assertion states that the angle of repose is equal to the angle of limiting friction.

- **Angle of Repose**: This is the maximum angle at which an object can remain at rest on an inclined surface without sliding down. It is denoted by the angle \( \theta \).
- **Angle of Limiting Friction**: This is the angle at which the force of static friction is at its maximum before the object begins to move.

### Step 2: Establish the Relationship
From physics, we know that the coefficient of static friction (\( \mu \)) is related to the angle of repose and the angle of limiting friction.

- The relationship can be expressed as:
\[ \mu = \tan(\theta) \]
where \( \theta \) is the angle of inclination of the surface.

### Step 3: Derive the Equality
When the object is on the verge of sliding, the angle of repose (\( \theta_r \)) and the angle of limiting friction (\( \theta_f \)) are equal.

- Therefore, we can say:
\[ \theta_r = \theta_f \]

This confirms that the assertion is true.

### Step 4: Understand the Reason
The reason states that when the body is just at the point of motion, the force of friction in this stage is called limiting friction.

- **Limiting Friction**: This is the maximum static friction force that must be overcome for the object to start moving.

### Step 5: Validate the Reason
When an object is on the verge of motion, the frictional force acting on it is indeed the limiting friction, which corresponds to the maximum static friction.

- This means that the reason provided is also true.

### Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion.

### Final Answer
The correct option is: **Both assertion and reason are true and reason is the correct explanation.**

---