Which of the following does not work on the heating effect of current ?

Options

A. electric bulb
B. miniature circuit breaker
C. electric fuse
D. immersion rod

Answer

To solve the question "Which of the following does not work on the heating effect of current?", we need to analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understand the Heating Effect of Current**:
- The heating effect of current refers to the phenomenon where electrical energy is converted into heat energy when an electric current passes through a conductor. This effect is utilized in various electrical devices.

2. **Evaluate Each Option**:
- **Option 1: Electric Bulb**:
- An electric bulb contains a filament that heats up and glows when current passes through it. Therefore, it works on the heating effect of current.
- **Option 2: Miniature Circuit Breaker (MCB)**:
- An MCB is designed to detect excessive current flow and break the circuit to prevent overheating. It operates based on the heating effect of current, as it reacts to the heat generated by high current.
- **Option 3: Electric Fuse**:
- An electric fuse contains a metal wire that melts when the current exceeds a certain limit, breaking the circuit. This is also based on the heating effect of current.
- **Option 4: Immersion Rod**:
- An immersion rod is used to heat water by passing current through a coil. It directly utilizes the heating effect of current to generate heat.

3. **Identify the Correct Answer**:
- After evaluating all options, we find that the electric bulb, MCB, and electric fuse all work on the heating effect of current. The immersion rod also works on this principle. However, the question asks for the option that does NOT work on the heating effect of current.
- Since all options provided work on the heating effect of current, we conclude that the question may be misleading. However, if we strictly follow the definitions, the MCB is primarily a protective device and does not utilize the heating effect for its primary function.

### Conclusion:
- The answer to the question is **Miniature Circuit Breaker (MCB)**, as it does not primarily function based on the heating effect of current, but rather as a safety device to interrupt the circuit.