Question

A certain power transformer has a turns ratio of 5. What voltage can you expect at the secondary winding when you apply 120 V to the primary winding?​

Answer 1

Given :

Turns ratio = 5

Voltage across primary coil = 120V

To Find :

Voltage across secondary coil.

Solution :

For an ideal transformer relation between turns ratio and voltage across coil is given by

$\star\:\:\underline{\boxed{\bf{\orange{\dfrac{V_s}{V_p}=k}}}}$

• k denotes turns/transformation ratio

• Vs denotes pd across secondary coil

• Vp denotes pd across primary coil

By substituting the values;

$:\implies\sf\:\dfrac{V_s}{V_p}=k$

$:\implies\sf\:\dfrac{V_s}{120}=5$

$:\implies\sf\:V_s=120\times 5$

$:\implies\:\underline{\boxed{\bf{\blue{V_s=600V}}}}$

Additional Information :

• A transformer is essentially an a.c. device.
• It cannot work on d.c. It changes voltages/currents.
• It does not affect the frequency of a.c.
• In the same way a step-down transformer changes a high voltage into a low voltage.