In which of the following application, eddy current has no role to play?

Options

A. Electric power meters
B. Induction furnace
C. LED lights
D. Magnetic brakes in trains

Explanation

To determine in which application eddy currents have no role to play, we need to understand what eddy currents are and where they are typically utilized.

### Step-by-Step Solution:

1. **Understanding Eddy Currents**:
- Eddy currents are loops of electrical current that are induced within conductors by a changing magnetic field due to Faraday's law of electromagnetic induction. When a conductor is placed in a varying magnetic field, it experiences an induced electromotive force (emf), leading to the flow of current in circular paths within the conductor.

2. **Applications of Eddy Currents**:
- Eddy currents are utilized in various applications, including:
- **Induction Heating**: Used in induction furnaces where the heat generated by eddy currents melts metals.
- **Electric Power Meters**: Eddy currents are used in the operation of some types of electric meters to measure power consumption.
- **Magnetic Braking**: Eddy currents are used in braking systems of trains and roller coasters, where they create a magnetic field that opposes motion.

3. **Identifying the Options**:
- The question provides options regarding applications where eddy currents may or may not play a role.
- We need to analyze each option to see if eddy currents are involved.

4. **Evaluating the Options**:
- **Option A**: Induction Heating - Eddy currents play a significant role.
- **Option B**: Electric Power Meters - Eddy currents are used here.
- **Option C**: Magnetic Braking - Eddy currents are involved in this application.
- **Option D**: LED Lights - LED lights operate on the principle of electroluminescence and do not involve eddy currents.

5. **Conclusion**:
- After evaluating the options, it is clear that **LED lights** (Option D) have no role for eddy currents. Therefore, the correct answer is **Option D**.

### Final Answer:
**Option D: LED Lights**