Electricity and Magnetism Complete

Which of the following is the reason “soft” iron is used for the cores of electromagnets?a.It is difficult to magnetize.

• It is difficult to magnetize
• It has no magnetic domains.
• It is a permanent magnet
• It is easily magnetized.

Which of the following is maintained across the terminals of a battery?

• a voltage drop
• an electric charge
• a potential difference
• a voltage drop and a potential difference

What is the unit of electric power?

• watt
• ampere
• ohm
• volt

If a neutral metal comb is held near an object with a negative charge, the comb will become charged by

• static discharge
• friction
• contact
• induction

If you know the power rating of an appliance and the voltage of the line it is attached to, you can calculate the current the appliance uses by

• voltage multiplied by power
• voltage divided by power
• subtract power from the voltage
• divide power by voltage

If an atom gains electrons, it becomes a _____.

• neutral ion
• positively charged ion
• negatively charged ion
• neutral atom

An electrical insulator has ____

• more protons than neutrons
• electrons tightly bound to its atoms
• negatively charged ions
• electrons that move freely.

Walking across a carpet is an example of charge being transferred by

• induction.
• contact.
• static electricity.
• friction.

The strength of an electric field depends on the

• amount of charge that produced the field.
• distance from the charge.
• amount of charge on a test charge placed in the field.
• distance from charge and amount of charge producing the field.

If a current-carrying wire is in a magnetic field, in what direction will a force be exerted on the wire?

• perpendicular to both the magnetic field and the current direction
• perpendicular to the current direction and parallel to the magnetic field
• parallel to both the current direction and the magnetic field
• perpendicular to the magnetic field and parallel to the current direction