Test #5

When the distance between two charges is halved, the electrical force between the charges

quadruples

A main difference between gravitational and electric forces is that electrical forces

repel or attract

Magnetism is due to the motion of electrons as they

revolve around the nucleus and spin on their axes

On some early automobiles both headlights went out when one bulb burned out. The headlights must have been connected in

series

An electromagnet

uses an electric current to produce a magnetic field

The electric power of a lamp that carries 2 A at 120 V is

240 watts

The expression that mathematically describes the force between two static electric charges is called

Coulomb's Law

The volt is the unit of electric

potential difference

The electric energy lost when a current passes through a resistance

becomes heat

When a magnetized bar of iron is strongly heated, its magnetization

becomes weaker

When an electric charge moves it produces

both an electric and magnetic field

To say that electric charge is conserved is to say that electric charge

can neither be created nor destroyed

Electric potential is the ratio of electric energy to amount of electic

charge

The magnetic field lines around a long straight wire carrying a current are

concentric circles around the current

An ampere is a unit of electrical

current

A balloon will stick to a wall if the balloon is charged

either positively or negatively

The particle easiest to remove from an atom is a(n)

electron

A negative ion has more

electrons than protons

In an electrically neutral atom the number of protons in the nucleus is equal to the number of

electrons that surround the nucleus

Heat a copper wire and its electric resistance

increases

Stretch a copper wire so that it is thinner and the resistance between its ends

increases

According to Ohm's Law, for a given voltage, the current is

inversely proportional to the resistance

An object has a positive electric charge whenever

it has a deficiency of electrons

Charge carriers in a metal are electrons rather than protons because electrons are

loosely bound

Rub electrons from your hair with a comb and the comb becomes

negatively charged