A step-down transformer with 110 turns in the secondary lowers the voltage from 20,000 V

A step-down transformer with 110 turns in the secondary lowers the voltage from 20,000 V to 110 V. How many turns are in its primary?

A transformer is an electrical device designed to change voltage. It can both reduce tension and increase. On the winding, where there are more turns, the voltage is higher. The dependence of the voltage on the number of turns is called the transformation ratio.
w1 / w2 = U1 / U2 = k, where w1 is the number of turns of the primary winding, U1 is the voltage in the primary winding, w2 is the number of turns of the secondary winding, U2 is the voltage of the secondary winding, k is the transformation ratio.
Let us express w1 from this expression:
w1 = w2 * U1 / U2
Substitute the numbers, determine the number of turns in the primary winding:
w1 = w2 * U1 / U2 = 110 * 20,000 / 110 = 20,000
Answer: there are 20,000 turns in the primary winding.