CPA 2 Review

Which statement describes the relationship between electric generators and electric motors?

• Both electric generators and electric motors use motion in a magnetic field to produce electric current

• Both electric generators and electric motors transform current from a magnetic field into mechanical energy.

• Generators transform mechanical energy into electrical energy whereas electric motors transform electric energy into mechanical energy

• Generators transform electrical energy into mechanical energy whereas electric motors transform mechanical energy into electrical energy.

An electromagnet can be created by wrapping a wire around a nail and attaching the two ends of the wire to a battery. What happens in an electromagnet

• Electrical energy transforms into mechanical energy

• Electrical energy produces a magnetic field

• Mechanical energy transforms into electrical energy

• Mechanical energy produces an electric field

Which statement is true about a simple electric motor?

• A simple electric motor produces an electric current when a coil of wire is wrapped around an iron core and is rotated near a magnet.

• A simple electric motor is formed when a wire in an electric circuit is wrapped around an iron core producing a magnetic field.

• A simple electric motor is a large wheel that rotates when pushed by water, wind, or steam.

• A simple electric motor uses a rotating coil of wire in a magnetic field to produce motion.

Fischer has an iron nail, a metal wire, and a battery and connects them as shown in the picture. Fischer moves a few iron filings towards the set up. What would most likely happen to the iron filings?

• They will be attracted to the nail.

• They will be repelled by the nail.

• They will be attracted to the battery

• They will be repelled from the battery

Which pair of objects will have the greatest force of gravity between them?

• objects that are large and far apart

• objects that are small and close together

• Objects that are small and far apart

• objects that are large and close together

A student has two magnets as shown. How can the student arrange the magnets to feel the force of repulsion?

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What force does not require contact and can act on objects from a distance?

• applied force

• gravitational force

• friction force

• tension force

What will happen if the force of gravitational attraction between the objects shown if one of the two objects is doubled in size?

• it will increase

• it will decrease

• it will stay the same

• it will repel

A student is making an electromagnet. Which substance should the student use to wrap a copper wire around?

• an iron nail

• a hard plastic tube

• a glass cylinder

• an aluminum spoon

Which modification would increase the magnetic strength of the electromagnet?

• using a thinner nail

• decreasing the length of the nail

• increasing the number of turns in the coil

• attaching both ends of the wire to one of the battery