NEIEP Mechanics Practice Exam

In a 100 volt 60Hz circuit, what is the total reactance with a 4 Henry inductor in the circuit?

1. 1000 ohms

2. 1200 ohms

3. 1507 ohms

4. 2000 ohms

The correct answer is: 1507 ohms

To find the total reactance in an AC circuit with a given inductor, the reactance of the inductor can be calculated using the formula: \[ X_L = 2 \pi f L \] where: - \( X_L \) is the inductive reactance in ohms, - \( f \) is the frequency in hertz, - \( L \) is the inductance in henries. Given that the frequency \( f \) is 60 Hz and the inductance \( L \) is 4 Henry, we can substitute these values into the formula: 1. Calculate \( 2 \pi f \): \[ 2 \pi \times 60 \approx 376.99 \, \text{rad/s} \] 2. Now, multiply by the inductance \( L \): \[ X_L = 376.99 \times 4 \approx 1507.96 \, \text{ohms} \] This value is typically rounded to 1507 ohms. This calculation reveals that the total reactance due to the 4 Henry inductor at a frequency of 60 Hz is approximately 1507 ohms, justifying