Question

If current drops from 4 A to 0 A in 0.5 s, and voltage is 120 V, find the self-inductance.

Hint:

The formula for self-inductance is derived from the relationship between voltage, current, and time in an inductor.

Answer 1

Step 1: Find the rate of change of current: \( \dfrac{dI}{dt} = \dfrac{4 - 0}{0.5} = 8 \, \text{A/s} \).
Step 2: The induced emf equation is \( V = L \dfrac{dI}{dt} \).
Step 3: Solve for \( L \): \[ L = \frac{120}{8} \] \[ \boxed{L = 15 \, \text{H}} \]