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: Understanding the formula.
The self-inductance \( L \) can be calculated using the formula: \[ L = \frac{V \Delta t}{\Delta I} \] where: - \( V \) is the voltage (120 V), - \( \Delta t \) is the time duration (0.5 s), - \( \Delta I \) is the change in current (from 4 A to 0 A, so \( \Delta I = 4 \, \text{A} \)). Step 2: Substituting the values.
Substituting the known values into the formula: \[ L = \frac{120 \times 0.5}{4} = \frac{60}{4} = 15 \, \text{H} \] Step 3: Conclusion.
Thus, the self-inductance is \( 15 \, \text{H} \).