A 0.5m long straight wire in which a current of 1.2A is flowing is kept a right angles to a uniform magnetic field of 2.0 tesla. The force acting on the wire will be-

Options

A. 2N
B. 2.4N
C. 1.2N
D. 3N

Explanation

To find the force acting on a straight 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 force acting on the wire (in Newtons),
- \( I \) is the current flowing through the wire (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 direction of the current and the magnetic field.

### Step-by-step solution:

1. **Identify the given values**:
- Length of the wire, \( L = 0.5 \, \text{m} \)
- Current, \( I = 1.2 \, \text{A} \)
- Magnetic field strength, \( B = 2.0 \, \text{T} \)
- Angle \( \theta = 90^\circ \) (since the wire is at right angles to the magnetic field)

2. **Substitute the values into the formula**:
\[ F = I \cdot L \cdot B \cdot \sin(\theta) \]
\[ F = 1.2 \, \text{A} \cdot 0.5 \, \text{m} \cdot 2.0 \, \text{T} \cdot \sin(90^\circ) \]

3. **Calculate \( \sin(90^\circ) \)**:
\[ \sin(90^\circ) = 1 \]

4. **Plug in the value of \( \sin(90^\circ) \)**:
\[ F = 1.2 \cdot 0.5 \cdot 2.0 \cdot 1 \]

5. **Perform the multiplication**:
- First, calculate \( 1.2 \cdot 0.5 = 0.6 \)
- Then, calculate \( 0.6 \cdot 2.0 = 1.2 \)

6. **Final result**:
\[ F = 1.2 \, \text{N} \]

Thus, the force acting on the wire is **1.2 Newtons**.