All the particles of a rigid rotating body move in a circular path when the axis of rotation:-

Options

A. passes through any point in the body
B. is situated outside the body
C. situated any where
D. passes through the centre of mass

Answer

To solve the question, we need to analyze the conditions under which all particles of a rigid rotating body move in a circular path. The options given are:

A) The axis of rotation passes through any point of the body.
B) The axis of rotation is situated outside the body.
C) The axis of rotation is situated anywhere.
D) The axis of rotation passes through the center of the rigid body.

Let's evaluate each option step by step:

### Step 1: Understanding Rigid Body Rotation
A rigid body is defined as a solid object in which the distance between any two particles remains constant regardless of the forces acting on it. When a rigid body rotates about an axis, all particles in the body will follow a circular path around that axis.

### Step 2: Analyzing Option A
**Option A:** The axis of rotation passes through any point of the body.
- If the axis of rotation passes through a point in the body, then that point will remain stationary (it will not move in a circular path). Other points will move in circular paths around this axis. Therefore, not all particles are moving in a circular path.
**Conclusion:** This option is incorrect.

### Step 3: Analyzing Option B
**Option B:** The axis of rotation is situated outside the body.
- If the axis of rotation is outside the body, all particles of the body will indeed move in circular paths around the axis. Each particle will trace a circle with a radius that depends on its distance from the axis.
**Conclusion:** This option is correct.

### Step 4: Analyzing Option C
**Option C:** The axis of rotation is situated anywhere.
- This option is vague. If the axis is inside the body, similar to option A, some particles may not move in a circular path. Therefore, this option does not guarantee that all particles will move in circular paths.
**Conclusion:** This option is incorrect.

### Step 5: Analyzing Option D
**Option D:** The axis of rotation passes through the center of the rigid body.
- If the axis of rotation passes through the center of the body, some particles will still remain stationary or will not move in a circular path. For example, particles located on the axis will not move in a circular path.
**Conclusion:** This option is incorrect.

### Final Answer
Based on the analysis, the correct answer is **B) The axis of rotation is situated outside the body.**

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