When a current is passed in moving coil galvanometer, the coil gets deflected because,

Options

A. current in the coil produces an electric field
B. a couple acts on coil
C. the current deflects any thing
D. current in the coil produces magnetic field

Answer

To answer the question, "When a current is passed in a moving coil galvanometer, the coil gets deflected because," we can break down the explanation into the following steps:

### Step-by-Step Solution:

1. **Understanding the Setup**:
- A moving coil galvanometer consists of a coil of wire that is free to rotate in a magnetic field. The coil is placed between the poles of a magnet, creating a strong magnetic field.

**Hint**: Visualize the arrangement of the coil and the magnetic field to understand how they interact.

2. **Current Flow in the Coil**:
- When an electric current flows through the coil, it generates its own magnetic field around it due to Ampere's law. The direction of this magnetic field can be determined using the right-hand rule.

**Hint**: Remember that current-carrying conductors generate magnetic fields that can interact with external magnetic fields.

3. **Interaction with External Magnetic Field**:
- The magnetic field produced by the current in the coil interacts with the external magnetic field provided by the magnets. This interaction leads to the generation of forces on the coil.

**Hint**: Think about how two magnetic fields can exert forces on each other.

4. **Net Force and Torque**:
- Although the net force acting on the coil can be zero (since forces on opposite sides of the coil can cancel each other out), there is a torque (or couple) acting on the coil. This torque is due to the unequal distribution of forces on different parts of the coil.

**Hint**: Consider how forces can create rotation even if they do not produce a net linear force.

5. **Resulting Deflection**:
- The torque causes the coil to rotate, leading to a deflection of the pointer attached to the coil. This deflection is proportional to the current flowing through the coil, allowing the galvanometer to measure the current.

**Hint**: Relate the deflection of the coil to the amount of current passing through it.

6. **Conclusion**:
- Therefore, the coil gets deflected because the current in the coil produces a magnetic field that interacts with the external magnetic field, resulting in a torque that causes the coil to rotate.

### Final Answer:
The coil gets deflected because the current in the coil produces a magnetic field that interacts with the external magnetic field, resulting in a torque that causes the coil to rotate.