We are asked to determine the current input for a transformer. To do that we will use the following formula:
[tex]\frac{I_p}{I_s}=\frac{V_s}{V_p}[/tex]Where:
[tex]\begin{gathered} I_p=\text{ primary or input current} \\ I_s=\text{ secondary or output current} \\ V_s=\text{ secondary voltage} \\ V_p=\text{ primary voltage} \end{gathered}[/tex]Now, we solve for the primary current by multiplying both sides by the secondary current:
[tex]I_p=I_s\frac{V_s}{V_p}[/tex]Now, we plug in the values:
[tex]I_p=(355mA)(\frac{12V}{120V})[/tex]Solving the operations:
[tex]I_p=35.5mA[/tex]Therefore, the output current is 35.5 mA.
Part b. To determine the power input we use the following formula:
[tex]P=VI[/tex]Since we want to determine the input power we use the value of primary current and voltage:
[tex]P=(0.355A)(120V)[/tex]Solving the operations:
[tex]P=42.6W[/tex]Therefore, the power is 42.6 Watts.
