Module 5 quiz

a magnet attracts

some substances and repels others

Direct electric current cannot be used to operate

transformers

When an observer moves past a stationary electric charge, she detects

both an electric and a magnetic field

The conventional unit of battery capacity is the ampere-hour, which is actually a unit of

electric charge

A kilowatt hour is a unit of

energy

The current with which a transformer is used

must be ac

When the voltage across a certain resistance is V, the power delivered is P. If the voltage is halved to V/2, the power delivered becomes

p/4

A molecule that has lost an electron becomes a

positive ion

A volt is a unit of electric:

potential difference

Which of the following statements is not true?

protons and electrons have equal masses

A current-carrying wire is in a magnetic field with the direction of the current parallel to that of the field.

the wire has no tendency to move or to turn

a current-carrying wire is in a magnetic field with the direction of the current perpendicular to that of the field

the wire tends to move perpendicular to the field

Relative to the electric force between two protons, the gravitational force between them is

weaker

Ohm's law

holds only for metals

Three 12-V batteries cannot be connected to give a voltage for the set of

6V

which of the following statements is not true?

a proton in an atom circulates around its nucleus

the electrons in an atom

are some distance away from the nucleus

When a current passes through a resistance, the electric energy that is lost

becomes heat

A negative electric charge

interacts with both positive and negative charges

A compass needle tends to

line up parallel to a magnetic field