Transformer Quiz

What is the primary function of a transformer?

• To convert AC to DC

• To increase or decrease voltage

• To store electrical energy

• To measure electrical current

Answer explanation

The primary function of a transformer is to increase or decrease voltage in an electrical circuit, allowing for efficient power distribution and usage. It does not convert AC to DC, store energy, or measure current.

Which principle explains the operation of a transformer?

• Ohm's Law

• Coulomb's Law

• Faraday's Law of Electromagnetic Induction

• Kirchhoff's Law

Answer explanation

A transformer operates based on Faraday's Law of Electromagnetic Induction, which states that a change in magnetic flux induces an electromotive force (EMF) in a coil. This principle is fundamental to transformer functionality.

What are the two main types of transformers?

• Step-up and Step-down

• Series and Parallel

• AC and DC

• Primary and Secondary

Answer explanation

The two main types of transformers are Step-up and Step-down. Step-up transformers increase voltage, while Step-down transformers decrease voltage, making them essential for efficient power transmission.

What is the purpose of the core in a transformer?

• To provide insulation

• To reduce resistance

• To provide a path for the magnetic flux

• To store electrical energy

Answer explanation

The core in a transformer provides a path for the magnetic flux generated by the primary winding. This enhances the efficiency of energy transfer to the secondary winding, making it essential for the transformer's operation.

What is the turns ratio in a transformer?

• The ratio of primary voltage to secondary voltage

• The ratio of the number of turns in the primary coil to the number of turns in the secondary coil

• The ratio of primary current to secondary current

• The ratio of input power to output power

Answer explanation

The turns ratio in a transformer specifically refers to the ratio of the number of turns in the primary coil to the number of turns in the secondary coil. This ratio determines the relationship between primary and secondary voltages.

Which type of transformer is used to increase voltage?

• Step-down transformer

• Isolation transformer

• Step-up transformer

• Auto transformer

Answer explanation

A step-up transformer is designed to increase voltage from a lower level to a higher level. In contrast, a step-down transformer decreases voltage, while an isolation transformer and auto transformer serve different purposes.

What is mutual induction in the context of transformers?

• The process of generating an EMF in a coil due to a change in current in the same coil

• The process of generating an EMF in a coil due to a change in current in a neighboring coil

• The process of converting AC to DC

• The process of converting electrical energy to mechanical energy

Answer explanation

Mutual induction occurs when a change in current in one coil induces an electromotive force (EMF) in a neighboring coil. This principle is fundamental to the operation of transformers, making the second choice correct.

What is the unit of measurement for transformer power rating?

• Watts

• Volts

• Amperes

• Volt-amperes (VA)

Answer explanation

The power rating of a transformer is measured in volt-amperes (VA), which accounts for both voltage and current. This distinguishes it from watts, which measures real power, making VA the correct unit for transformers.

What is the purpose of laminating the core of a transformer?

• To increase the core's strength

• To reduce eddy current losses

• To increase the core's weight

• To reduce the core's size

Answer explanation

The purpose of laminating the core of a transformer is to reduce eddy current losses. Laminations are thin sheets of metal that limit the flow of these currents, improving efficiency and reducing heat generation.

Which component of a transformer is responsible for transferring electrical energy from one circuit to another?

• The core

• The windings

• The insulation

• The terminals

Answer explanation

The windings of a transformer consist of coils of wire that create magnetic fields when electrical current flows through them. This magnetic field induces voltage in the secondary winding, transferring electrical energy between circuits.