Which of the following devices does not convert electrical energy into mechanical energy ?

Options

A. Vacuum cleaner
B. Washing machine
C. Mixer
D. Speaker

Explanation

To solve the question "Which of the following devices does not convert electrical energy into mechanical energy?", we will analyze each option provided.

### Step-by-Step Solution:

1. **Identify the devices**: We need to look at the list of devices given in the options. The devices mentioned are:
- Vacuum Cleaner
- Washing Machine
- Mixer
- Speaker

2. **Analyze the first device - Vacuum Cleaner**:
- A vacuum cleaner takes electrical energy as input and converts it into mechanical energy to operate its motor, which creates suction. Therefore, it converts electrical energy into mechanical energy.

3. **Analyze the second device - Washing Machine**:
- A washing machine also takes electrical energy and converts it into mechanical energy to rotate the drum for washing clothes. Hence, it converts electrical energy into mechanical energy.

4. **Analyze the third device - Mixer**:
- A mixer uses electrical energy to power its motor, which then converts that energy into mechanical energy to blend or mix ingredients. Thus, it also converts electrical energy into mechanical energy.

5. **Analyze the fourth device - Speaker**:
- A speaker takes electrical energy and converts it into sound energy. It does not perform any mechanical work in the traditional sense of moving parts for a mechanical purpose. Therefore, it does not convert electrical energy into mechanical energy.

6. **Conclusion**:
- Based on the analysis, the device that does not convert electrical energy into mechanical energy is the **Speaker**.

### Final Answer:
The correct answer is **Speaker**.

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