kVA Rating of Transformers

Why are transformers rated in kVA instead of Watts?

• Because loads are purely resistive

• Because it simplifies calculations

• Because it reduces energy consumption

• Because loads are not purely resistive

What principle do transformers use in their operation?

• Resistive loading

• Direct current

• Mutual induction

• Capacitive coupling

What type of load does a transformer represent?

• None of the above

• Resistive

• Capacitive

• Inductive

Why do transformers produce reactive power?

• Due to resistive loads

• Because they are 100% efficient

• Due to mutual induction

• Because they only use AC current

What does the kVA rating of a transformer tell us?

• The amount of true power it produces

• The efficiency of the transformer

• The amount of current it can deliver without overheating

• The maximum voltage it can handle

How do you calculate the kVA of a transformer?

• Multiply the voltage by the current and divide by 1000

• Divide the voltage by the current

• Add the voltage to the current

• Multiply the primary voltage by the primary current

What is the significance of voltage and current being in-phase in resistive loads?

• Both B and C

• It indicates high efficiency

• It means there is no reactive power

• It signifies that the load is purely resistive

Why is kVA used instead of kW for transformers?

• Because transformers only operate in AC

• Because it accounts for the inductive element of power

• Because kVA is easier to calculate

• Because kW is a less accurate measurement

What happens when voltage and current are out-of-phase?

• It indicates a purely resistive load

• Reactive power is present

• The transformer becomes more efficient

• It reduces the inductive reactance

Is the kVA rating the same for both primary and secondary windings of a transformer?

• Only in three-phase transformers

• Only in single-phase transformers

• No, it varies significantly

• Yes, it is the same