If a transformer's primary is rated at 120 volts and its secondary at 12 volts, what is the turns ratio?

If a transformer's primary is rated at 120 volts and its secondary at 12 volts, what is the turns ratio?

• A. 5:1
• B. 10:1
• C. 8:1
• D. 12:1

Answer: (B)

To find the turns ratio of a transformer, you can use the formula that states the turns ratio is equal to the primary voltage divided by the secondary voltage. In this case, the primary voltage is 120 volts and the secondary voltage is 12 volts. Using the formula: Turns Ratio = Primary Voltage / Secondary Voltage Substituting the values: Turns Ratio = 120 volts / 12 volts = 10 Thus, the turns ratio of this transformer is 10:1. This means that for every 10 turns of wire on the primary side, there is 1 turn on the secondary side. This ratio indicates how the voltage is transformed; stepping down from a higher voltage (120 volts) to a lower voltage (12 volts) involves reducing the number of turns on the secondary relative to the primary. Understanding this concept is crucial for working with transformers, as it helps in selecting the appropriate transformer for specific applications based on input and output voltage requirements.

To find the turns ratio of a transformer, you can use the formula that states the turns ratio is equal to the primary voltage divided by the secondary voltage. In this case, the primary voltage is 120 volts and the secondary voltage is 12 volts.

Using the formula:

Turns Ratio = Primary Voltage / Secondary Voltage

Substituting the values:

Turns Ratio = 120 volts / 12 volts = 10

Thus, the turns ratio of this transformer is 10:1. This means that for every 10 turns of wire on the primary side, there is 1 turn on the secondary side. This ratio indicates how the voltage is transformed; stepping down from a higher voltage (120 volts) to a lower voltage (12 volts) involves reducing the number of turns on the secondary relative to the primary.

Understanding this concept is crucial for working with transformers, as it helps in selecting the appropriate transformer for specific applications based on input and output voltage requirements.