Answer to Question #112993 in Electricity and Magnetism for Aliyah

Question

An electrical mini speaker for home requires 9 V to function. The voltage of the electrical supply is 240 V. What is the turns ratio of the transformer that must be used?

Answer 1

From the formula for the transformation coefficient

$k=\frac{U_1}{U_2}=\frac{N_1}{N_2}$

the ratio of the number of turns of the transformer is equal

$\frac{N_1}{N_2}=\frac{U_1}{U_2}=\frac{240}{9}=26.67$