Electricity Transformers

What does the "H1" marking on a current transformer indicate?

Proper polarity side facing the generator

What defines the exciting or magnetizing current in a transformer?

Current that magnetizes the core even without load

What happens to primary current when the secondary load is increased?

Primary current increases

Which law best describes the induction of voltage in a secondary coil due to changing magnetic flux?

Faraday's Law

Which type of transformer is designed to work within the 20-20,000 cps frequency range?

Audio transformer

Which transformer type uses a single winding as both primary and secondary?

Autotransformer

In a transformer with a turns ratio of 1:4, what effect does this have?

Step-up voltage, step-down current

Which transformer type is most commonly used in aviation electrical systems?

Voltage transformers

Why are transformer cores laminated?

To reduce eddy current losses

In a step-up transformer, what happens to the current when voltage is increased?

Current decreases proportionally

What type of current transformers are typically used in power systems?

Ring-type transformers

What role does the iron core play in a transformer?

It provides a low-reluctance path for magnetic flux

In long-distance power transmission, why is voltage stepped up at the source?

To reduce line losses during transmission

How does Lenz's Law apply in transformer operation?

Secondary current opposes the primary flux

Why can a transformer not operate on pure DC voltage?

DC produces no varying magnetic field

What is the coefficient of coupling in a transformer?

Ratio of secondary flux to primary flux

What is hysteresis loss in a transformer core?

Energy required to magnetize and demagnetize the core

Which transformer type is typically used in radio-frequency circuits?

RF transformer

What causes leakage flux in a transformer?

Incomplete linkage of magnetic lines between coils

Why must the secondary of a current transformer never be left open?

It can create dangerously high voltages

What ensures different voltages can be supplied by a single transformer?

Secondary windings with center taps

Why is power considered conserved in an ideal transformer?

Because total power in equals total power out, minus losses

What is the primary energy loss caused by resistance in the windings?

Copper loss

Which factor determines whether a transformer is step-up or step-down?

Turns ratio between primary and secondary

What fundamental principle allows a transformer to transfer energy between two coils?

Mutual induction of magnetic fields