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