Question

The magnetic engery stored in an inductor of inductance 4μH carrying a current of 2 A is:

• A. 4μJ
• B. 4μJ
• C. 4mJ
• D. 8μJ

Answer 1

The Correct Option is D

To calculate the magnetic energy stored in an inductor, we use the formula for energy stored in an inductor: \[ E = \frac{1}{2}LI^2 \] where \( E \) is the energy in joules, \( L \) is the inductance in henries (H), and \( I \) is the current in amperes (A).

Given that the inductance \( L \) is 4μH (microhenries) and the current \( I \) is 2 A, we convert 4μH to henries:

4μH = 4 × 10^-6 H

Substitute these values into the formula:

\[ E = \frac{1}{2} \times 4 \times 10^{-6} \times (2)^2 \]

Calculate the current squared:

2² = 4

Substitute back into the equation:

\[ E = \frac{1}{2} \times 4 \times 10^{-6} \times 4 \]

\[ E = 8 \times 10^{-6} \text{ J} \]

Therefore, the magnetic energy stored in the inductor is 8μJ (microjoules). The correct answer is 8μJ.