Which device is used to detect current in the circuit ?

Options

A. Galvanometer
B. Ammeter
C. Cyclotron
D. Voltmeter

Explanation

To determine which device is used to detect current in a circuit, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Devices**:
- We need to identify the devices mentioned: galvanometer, ammeter, cyclotron, and voltmeter.

2. **Define Each Device**:
- **Galvanometer**: A device that detects small currents and indicates their presence.
- **Ammeter**: A device that measures the current flowing in a circuit, typically designed for larger currents.
- **Cyclotron**: A particle accelerator, not used for measuring current.
- **Voltmeter**: A device that measures voltage, not current.

3. **Identify the Purpose of Each Device**:
- The question specifically asks for a device that detects current.
- Both the galvanometer and ammeter can measure current, but the galvanometer is specifically designed to detect the presence of small currents.

4. **Consider the Context of the Question**:
- The question asks for the device that is primarily used to detect current, not necessarily measure it in a quantitative manner.
- Since the galvanometer is used to detect the presence of current, it is the most appropriate answer.

5. **Conclusion**:
- Based on the definitions and purposes of the devices, the most suitable answer to the question is the **galvanometer**.

### Final Answer:
The device used to detect current in the circuit is the **galvanometer**.