Chapter SH, Problem 7.2APP

To determine

To calculate: Ratio of number of turns in the primary coil to the number of turns in the secondary coil.

Answer to Problem 7.2APP

Ratio of number of turns in the primary coil to the number of turns in the secondary coil is $\underset{\_}{20:1}$ .

Explanation of Solution

Given:

Input voltage = $2400\text{ V}$

Output voltage = $120\text{ V}$

Formula used:

Transformer voltage equation is given by,

  $\frac{V_{\text{out}}}{V_{\text{in}}}=\frac{N_2}{N_1}$

Where $V_{\text{out}}$ is output voltage, $V_{\text{in}}$ is input voltage, $N_2$ is number of turns in the secondary coil and $N_1$ is number of turns in the primary coil.

Calculation:

Ratio of number of turns in the primary coil to the number of turns in the secondary coil is calculated as:

  $\begin{array}{l}\frac{V_{\text{out}}}{V_{\text{in}}}=\frac{N_2}{N_1}\\ \frac{N_1}{N_2}=\frac{V_{\text{in}}}{V_{\text{out}}}\\ \frac{N_1}{N_2}=\frac{2400\text{ V}}{120\text{ V}}\\ \frac{N_1}{N_2}=\frac{20}{1}\end{array}$

Conclusion:

Ratio of number of turns in the primary coil to the number of turns in the secondary coil is $\underset{\_}{20:1}$ .