Question

A coil of 100 turns, carrying a current of 5A, is placed in a magnetic field of 2T. The area of each turn is 0.01 m\(^2\). What is the magnetic moment of the coil?

• A. 0.5 Am\(^2\)
• B. 5 Am\(^2\)
• C. 2 Am\(^2\)
• D. 1 Am\(^2\)

Hint:

Remember: The magnetic moment of a coil is directly proportional to the number of turns, the current, and the area of each turn.

Answer 1

The Correct Option is B

Coil's Magnetic Moment

The following data is provided:

• Number of turns: \( N = 100 \)
• Current: \( I = 5 \, \text{A} \)
• Magnetic field: \( B = 2 \, \text{T} \)
• Area per turn: \( A = 0.01 \, \text{m}^2 \)

Step 1: State the formula for a coil's magnetic moment:

The magnetic moment \( \mu \) of a coil is calculated using:

\[ \mu = N \cdot I \cdot A \]

Definitions:

• \( \mu \) = magnetic moment
• \( N \) = number of turns
• \( I \) = current
• \( A \) = area of each turn

Step 2: Input the given values into the formula:

\[ \mu = 100 \cdot 5 \cdot 0.01 = 5 \, \text{A} \cdot \text{m}^2 \]

Result:

The coil's magnetic moment is \( 5 \, \text{A} \cdot \text{m}^2 \).