1.2 amp current is flowing in a wire of 0.3 m length, It is placed perpendicular to the magnetic field (identical to 2T). The force acting on the wire will be:

Options

A. 1N
B. 0.72N
C. 0
D. 2N

Answer

To find the force acting on a wire carrying a current in a magnetic field, we can use the formula:

\[ F = I \cdot L \cdot B \cdot \sin(\theta) \]

Where:
- \( F \) is the magnetic force,
- \( I \) is the current in amperes,
- \( L \) is the length of the wire in meters,
- \( B \) is the magnetic field strength in teslas,
- \( \theta \) is the angle between the wire and the magnetic field.

### Step-by-Step Solution:

1. **Identify the given values:**
- Current, \( I = 1.2 \, \text{A} \)
- Length of the wire, \( L = 0.3 \, \text{m} \)
- Magnetic field strength, \( B = 2 \, \text{T} \)
- Angle \( \theta = 90^\circ \) (since the wire is perpendicular to the magnetic field)

2. **Convert the angle to sine value:**
- Since \( \theta = 90^\circ \), we know that \( \sin(90^\circ) = 1 \).

3. **Substitute the values into the formula:**
\[ F = I \cdot L \cdot B \cdot \sin(\theta) = 1.2 \, \text{A} \cdot 0.3 \, \text{m} \cdot 2 \, \text{T} \cdot 1 \]

4. **Calculate the force:**
\[ F = 1.2 \cdot 0.3 \cdot 2 = 0.72 \, \text{N} \]

5. **Final Result:**
The force acting on the wire is \( 0.72 \, \text{N} \).