3-27-24

Which of the following is a form of electromagnetic induction? *

• producing electric current by moving a magnet through a wire loop

• using an electromagnet to measure electric current

• producing mechanical energy by sending electric current through an electromagnet

• changing electrical energy to mechanical energy that produces sound

Which of the following devices produces electric current?

• generator

• stereo speaker

• galvanometer

• electric motor

Which of the following best describes how electricity is generated for homes?

• The spinning of a windmill's blades creates electric current without a generator.

• Nuclear reactions produce an electric current inside the reaction chamber.

• Steam pushes turbine blades in a generator, which changes the mechanical energy into electrical energy.

• Water released from a dam generates electric current, which is transformed into mechanical energy.

Which of the following devices can increase or decrease the voltage of an alternating current?

• generator

• transformer

• battery

• galvanometer

Why do power plants commonly produce alternating current?

• The voltage of alternating current can be increased or decreased with a transformer.

• It is less hazardous to use than direct current.

• Direct current requires the use of transformers.

• Less resistance is created in the wire.

Which direction is the North Pole of this electromagnet?

• Right

• Up

• Left

• Down

What is direct current?

• The flow of electric charge in only one direction.

• The flow of electric charge in a circular motion.

• The flow of electric charge in both directions.

• The flow of electric charge in a zigzag pattern.

What is the main difference between AC and DC?

• Color of wires

• Frequency of current

• Voltage level

• Direction of electric charge flow

An electric current that continually reverses direction over time is known as a(n)

• direct current

• alternating current

• simple current

A transformer has an input voltage of 12 V. The turns in the secondary coil are 20. The turns in the primary coil are 2. What is the output voltage?

• 120 V

• 1.2 V

• 12 V

• 0.83 V