Heating, Ventilation, and Air Conditioning (HVAC ) Electrical Practice Test

What will be the output voltage of a transformer with 1,000 turns in the primary coil and 2,000 turns in the secondary coil when 120 volts are applied?

1. 60 volts

2. 120 volts

3. 240 volts

4. 480 volts

The correct answer is: 240 volts

The output voltage of a transformer can be determined using the turns ratio formula, which is based on the relationship between the number of turns in the primary coil and the secondary coil. The formula is: \[ \frac{V_s}{V_p} = \frac{N_s}{N_p} \] Where \(V_s\) is the secondary voltage, \(V_p\) is the primary voltage, \(N_s\) is the number of turns in the secondary coil, and \(N_p\) is the number of turns in the primary coil. In this case, the primary coil has 1,000 turns and the secondary coil has 2,000 turns. The primary voltage is given as 120 volts. Plugging the values into the formula gives: \[ \frac{V_s}{120 \, \text{volts}} = \frac{2000 \, \text{turns}}{1000 \, \text{turns}} \] This simplifies to: \[ \frac{V_s}{120} = 2 \] To find the secondary voltage \(V_s\), multiply both sides by 120: \[ V_s = 2 \times 120 =