Transformer Fundamentals: Voltage, Current, and…

Q: What is the primary function of a transformer?

To change the voltage level of an AC supply. — Transformers primarily alter voltage levels using electromagnetic induction.

Q: The turns ratio (N) of a transformer is defined as:

Np / Ns — Turns ratio is the ratio of primary turns to secondary turns.

Q: If the primary voltage (Vp) is 120V and the secondary voltage (Vs) is 240V, the transformer is a:

Step-up transformer. — Vs > Vp indicates a step-up transformer.

Q: In an ideal transformer, the relationship between primary and secondary voltages (Vp and Vs) and turns (Np and Ns) is:

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

Q: If a transformer has a turns ratio of 2:1 (Np:Ns) and a primary voltage of 100V, what is the secondary voltage?

50V — Since Np > Ns, it's a step-down transformer; Vs = Vp * (Ns/Np) = 100 * (1/2) = 50V.

Q: In an ideal transformer, the power in the primary coil is ____ the power in the secondary coil.

equal to — Ideal transformers assume no power losses, so input power equals output power.

Q: If a transformer steps up the voltage, it will ____ the current.

step down — Power is conserved, so if voltage increases, current must decrease.

Q: What is the relationship between primary current (Ip) and secondary current (Is) in an ideal transformer?

Ip/Is = Ns/Np — Current ratio is inversely proportional to turns ratio, due to power considerations.

Q: A transformer with a turns ratio of 1:1 is used primarily for:

Isolation and impedance matching. — 1:1 transformers are typically used for isolation and impedance matching.

Q: If a transformer's primary current is 2A and the secondary current is 4A, what is the approximate turns ratio (Np:Ns)?

2:1 — Since Is is greater than Ip, it's a step-down; turns ratio = Ip/Is = 2/4 = 1/2, so Np:Ns is 2:1.

Question 1 of 10

What is the primary function of a transformer?

Transformers primarily alter voltage levels using electromagnetic induction.

Question 2 of 10

The turns ratio (N) of a transformer is defined as:

Turns ratio is the ratio of primary turns to secondary turns.

Question 3 of 10

If the primary voltage (Vp) is 120V and the secondary voltage (Vs) is 240V, the transformer is a:

Vs > Vp indicates a step-up transformer.

Question 4 of 10

In an ideal transformer, the relationship between primary and secondary voltages (Vp and Vs) and turns (Np and Ns) is:

Voltage ratio is directly proportional to the turns ratio.

Question 5 of 10

If a transformer has a turns ratio of 2:1 (Np:Ns) and a primary voltage of 100V, what is the secondary voltage?

Since Np > Ns, it's a step-down transformer; Vs = Vp * (Ns/Np) = 100 * (1/2) = 50V.

Question 6 of 10

In an ideal transformer, the power in the primary coil is ____ the power in the secondary coil.

Ideal transformers assume no power losses, so input power equals output power.

Question 7 of 10

If a transformer steps up the voltage, it will ____ the current.

Power is conserved, so if voltage increases, current must decrease.

Question 8 of 10

What is the relationship between primary current (Ip) and secondary current (Is) in an ideal transformer?

Current ratio is inversely proportional to turns ratio, due to power considerations.

Question 9 of 10

A transformer with a turns ratio of 1:1 is used primarily for:

1:1 transformers are typically used for isolation and impedance matching.

Question 10 of 10

If a transformer's primary current is 2A and the secondary current is 4A, what is the approximate turns ratio (Np:Ns)?

Since Is is greater than Ip, it's a step-down; turns ratio = Ip/Is = 2/4 = 1/2, so Np:Ns is 2:1.

Transformer Fundamentals: Voltage, Current, and Turns Ratio Quiz