Transformer Turns Ratio and Voltage Calculations…

Q: What is the relationship between the primary and secondary voltages in an ideal transformer?

Directly proportional to the turns ratio — Voltage ratio is directly proportional to the turns ratio (Vp/Vs = Np/Ns).

Q: If a transformer has 100 turns on the primary and 10 turns on the secondary, what is the turns ratio?

10:1 — Turns ratio is calculated as primary turns to secondary turns (100/10 = 10:1).

Q: A transformer has a turns ratio of 2:1. If the primary voltage is 120V, what is the secondary voltage?

60V — Vs = Vp / turns ratio (120V / 2 = 60V). This is a step-down transformer.

Q: A transformer steps down the voltage from 240V to 24V. If the primary has 1000 turns, how many turns does the secondary have?

100 — Ns = Np * (Vs/Vp) = 1000 * (24/240) = 100 turns.

Q: If a transformer's primary voltage is 240V and the secondary voltage is 480V, what type of transformer is it?

Step-up transformer — Voltage increases from primary to secondary, indicating a step-up transformer.

Q: What happens to the current in a transformer when the voltage is stepped up?

Decreases — In an ideal transformer, power (V*I) remains constant. So current decreases when voltage increases.

Q: Which of the following formulas correctly describes the relationship between primary and secondary voltage and turns ratio?

Vp/Vs = Np/Ns — The correct formula represents the direct proportionality.

Q: A transformer has a primary voltage of 120V, and a turns ratio of 1:4. Calculate the secondary voltage.

480V — Vs = Vp * (Ns/Np) = 120V * (4/1) = 480V (step-up).

Q: If a transformer's primary current is 2A and the turns ratio is 1:2 (step-up), what is the secondary current (assuming an ideal transformer)?

1A — Current is inversely proportional to the turns ratio (Is = Ip / (Ns/Np) = 2A / 2 = 1A).

Q: What is the primary function of a transformer?

To change the voltage level of AC voltage — The primary role is voltage transformation (step-up or step-down) with frequency remaining constant.

Question 1 of 10

What is the relationship between the primary and secondary voltages in an ideal transformer?

Voltage ratio is directly proportional to the turns ratio (Vp/Vs = Np/Ns).

Question 2 of 10

If a transformer has 100 turns on the primary and 10 turns on the secondary, what is the turns ratio?

Turns ratio is calculated as primary turns to secondary turns (100/10 = 10:1).

Question 3 of 10

A transformer has a turns ratio of 2:1. If the primary voltage is 120V, what is the secondary voltage?

Vs = Vp / turns ratio (120V / 2 = 60V). This is a step-down transformer.

Question 4 of 10

A transformer steps down the voltage from 240V to 24V. If the primary has 1000 turns, how many turns does the secondary have?

Ns = Np * (Vs/Vp) = 1000 * (24/240) = 100 turns.

Question 5 of 10

If a transformer's primary voltage is 240V and the secondary voltage is 480V, what type of transformer is it?

Voltage increases from primary to secondary, indicating a step-up transformer.

Question 6 of 10

What happens to the current in a transformer when the voltage is stepped up?

In an ideal transformer, power (V*I) remains constant. So current decreases when voltage increases.

Question 7 of 10

Which of the following formulas correctly describes the relationship between primary and secondary voltage and turns ratio?

The correct formula represents the direct proportionality.

Question 8 of 10

A transformer has a primary voltage of 120V, and a turns ratio of 1:4. Calculate the secondary voltage.

Vs = Vp * (Ns/Np) = 120V * (4/1) = 480V (step-up).

Question 9 of 10

If a transformer's primary current is 2A and the turns ratio is 1:2 (step-up), what is the secondary current (assuming an ideal transformer)?

Current is inversely proportional to the turns ratio (Is = Ip / (Ns/Np) = 2A / 2 = 1A).

Question 10 of 10

What is the primary function of a transformer?

The primary role is voltage transformation (step-up or step-down) with frequency remaining constant.

Transformer Turns Ratio and Voltage Calculations Quiz