While out for a walk with his mother, Lance notices a large, cylindrical gray box high atop a telephone pole. His mother explains that it is a transformer. This transformer takes 6000V from the power company and steps it down to the 240 V supplied to each of the houses on the street, with the use of a secondary coil containing 100 turns. How many turns are there in the primary coil?

Question

Physics

Francesca Jacobson

4 September, 17:35

While out for a walk with his mother, Lance notices a large, cylindrical gray box high atop a telephone pole. His mother explains that it is a transformer. This transformer takes 6000V from the power company and steps it down to the 240 V supplied to each of the houses on the street, with the use of a secondary coil containing 100 turns. How many turns are there in the primary coil?

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Answers (1)

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Viviana Parker · Answer 1

The primary coil of the transformer has 2500 turns.

Explanation:

A step-down transformer is an electrical device which is used to decrease the voltage of electricity.

It consists of two coils with different number of turns.

number of turns on a coil is directly proportional to voltage.

The ratio of Number of turns = Ratio of voltage changed

Let Np = number of turns in primary coil = ?

Ns = number of turns in secondary coil = 100

Vi = Voltage taken by Transformer = 6000

Vf = Voltage after transformation = 240 V

Now, we know that:

Np/Ns = Vi/Vf

⇒ Np = (Vi/Vf) * Ns

Np = (6000/240) * 100

Np = 2500 turns