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A transformer changes 120 V across the primary to 1200 V across the secondary. If the secondary coil has 800 turns, how many turns does the primary coil have?
(a) 40
(b) 80
(c) 100
(d) 400
(e) 4000

Respuesta :

fabianb4235

Answer:

the answer is B 80turns

Explanation:

Hello!

Remember that a transformer is an electrical device that allows you to change the voltage and current levels keeping the electric power constant, in this order of ideas the equation that governs this device is as follows

[tex]\frac{Vs}{Vp} =\frac{Ns}{Np}\\[/tex]

where

Vp= primary voltage=120V

Vs= secondary voltage=1200V

Ns=turns of secondary=800

Np=turns of primary

now we solve for Np

[tex]\frac{Vs}{Vp} =\frac{Ns}{Np}\\\\Np=Ns\frac{Vp}{Vs} \\[/tex]

[tex]Np=800\frac{120}{1200}=80turns[/tex]

the answer is B 80turns

asuwafohjames

The number of turns in the primary coil of the transformer is 80 turns. The right option is (b) 80

To calculate the number of turns in the primary coil of the transformer, we use the formula below.

Formula:

  • V/V' = N/N'................ Equation 1

Where:

  • V = Voltage of the primary supply
  • V' = Voltage of the secondary supply
  • N = number of turns in the primary coil
  • N' = number of turns in the secondary coil.

Make N the subject of the equation

  • N = VN'/V'......................... Equation 2

From the question,

Given:

  • V = 120 V
  • V' = 1200 V
  • N' = 800 turns

Substitute these values into equation 2

  • N = (120×800)/1200
  • N = 80 turns.

Hence, the number of turns in the primary coil of the transformer is 80 turns. The right option is (b) 80.
Learn more about transformers here: https://brainly.com/question/1312500