Transformer Quiz

What is the main function of a transformer?

• To convert AC to DC

• To increase or decrease voltage levels

• To store electrical energy

• To generate electricity

If the primary coil of a transformer has 400 turns and the secondary coil has 200 turns, what is the voltage ratio?

• 1:1

• 2:1

• 1:2

• 4:1

In a step-up transformer:

• Secondary voltage is higher than primary voltage

• Secondary voltage is lower than primary voltage

• Primary and secondary voltage are equal

• It converts AC to DC

The efficiency of an ideal transformer is:

• Less than 50%

• About 75%

• 100%

• More than 100%

A transformer with a turn ratio of 1:10 is a:

• Step-down transformer

• Isolation transformer

• Step-up transformer

• Auto-transformer

Why are transformers not used with direct current (DC)?

• DC is too powerful

• Transformers only work with constant current

• DC does not produce a changing magnetic field

• DC generates too much heat in transformers

The power output of an ideal transformer is:

• Always less than the input power

• Always greater than the input power

• Equal to the input power

• Dependent on the current flow

What is the relationship between current and voltage in a transformer?

• They are directly proportional

• They are inversely proportional

• They are unrelated

• They are always equal

If the input voltage of a transformer is 240 V and the primary coil has 480 turns, how many turns must the secondary coil have to produce an output of 120 V?

• 240 turns

• 120 turns

• 60 turns

• 960 turns

Which material is commonly used for the core of a transformer to reduce energy losses?

• Aluminum

• Iron

• Copper

• Steel