Question

A multipurpose transformer has a secondary coil with several points at which a voltage can be extracted, giving outputs of 5.60, 12.0, and 480 V. The input voltage is 240 V to a primary coil of 280 turns. What are the numbers of turns in the parts of the secondary used to produce the output voltages?

a) 1120 turns, 240 turns, 5 turns
b) 80 turns, 20 turns, 1 turn
c) 420 turns, 100 turns, 4 turns
d) 560 turns, 120 turns, 2 turns

Answer 1

To produce the output voltages of 5.60 V, 12.0 V, and 480 V, the numbers of turns in the parts of the secondary are 6 turns, 14 turns, and 560 turns, respectively.

Step-by-step explanation:

To determine the numbers of turns in the parts of the secondary used to produce the output voltages, we can use the turns voltage ratio. The turns voltage ratio is the same as the voltage ratio. We have a primary coil with 280 turns and an input voltage of 240 V, and three secondary voltages: 5.60 V, 12.0 V, and 480 V. Let's calculate the number of turns for each output voltage:

1. For the 5.60 V output: The turns voltage ratio is 240 V / 5.60 V = 42.86. To calculate the turns, we divide the number of turns in the primary coil by the turns voltage ratio: 280 turns / 42.86 = 6.52 turns. Since we can't have a fraction of a turn, the number of turns used to produce the 5.60 V output is 6 turns.
2. For the 12.0 V output: The turns voltage ratio is 240 V / 12.0 V = 20.00. Dividing the number of turns in the primary coil by the turns voltage ratio: 280 turns / 20.00 = 14.00 turns. Rounding to the nearest whole number, the number of turns used to produce the 12.0 V output is 14 turns.
3. For the 480 V output: The turns voltage ratio is 240 V / 480 V = 0.50. Dividing the number of turns in the primary coil by the turns voltage ratio: 280 turns / 0.50 = 560.00 turns. The number of turns used to produce the 480 V output is 560 turns.