In moving machine with different moving parts friction .....X..... the relative motion, and power dissipated in the form of ...Y....Here X and Y refers to

Options

A. favour, heat
B. favour, light
C. opposes, heat
D. opposes, light

Answer

To solve the question, we need to fill in the blanks X and Y in the statement: "In moving machine with different moving parts friction .....X..... the relative motion, and power dissipated in the form of ...Y...."

### Step-by-step Solution:

1. **Understanding Friction's Role**:
- Friction is a force that acts between two surfaces in contact. Its primary role is to oppose the relative motion between these surfaces.
- Therefore, for the blank X, we need a term that describes this function of friction.

**Conclusion for X**: The correct term for X is "Opposes".

2. **Analyzing Power Dissipation**:
- When machines operate, they often lose energy due to friction. This energy is typically dissipated in the form of heat.
- In mechanical systems, the energy lost due to friction is not converted into useful work but rather manifests as thermal energy (heat).

**Conclusion for Y**: The correct term for Y is "Heat".

3. **Final Statement**:
- Combining our findings, we can fill in the blanks: "In moving machine with different moving parts friction **opposes** the relative motion, and power dissipated in the form of **heat**."

4. **Selecting the Correct Option**:
- Now, we match our findings with the provided options:
- A) Favour and Heat
- B) Favour and Light
- C) Opposes and Heat
- D) Opposes and Light
- The correct option that matches our conclusions is **C) Opposes and Heat**.

### Final Answer:
- X = Opposes
- Y = Heat
- Correct option: C) Opposes and Heat