Unit 9 Test

If the strength of the magnetic field at A is 200 units and the strength of the magnetic field at B is 50 units, what is the distance to B?

10 Units

A 500-watt vacuum cleaner is plugged into a 120-volt outlet and used for 30 minutes. How much current runs through the vacuum?

4.2 amps

If the strength of the magnetic field at B is 20 units, the strength of the magnetic field at A is _____.

80 Units

Why is current supplied to consumers from generating plants in the form of alternating current?

It is a much more efficient mode of transmitting electricity than direct current.

Which of the following statements are true?

Positively charged objects attract negatively charged objects. Negatively charged objects attract neutral objects. Positively charged objects attract neutral objects.

A large electrostatic generator is commonly called a(n) _____.

Van de Graaff generator

In which of the following circumstances would a current register on the galvanometer?

a magnet being pushed through a solenoid a magnet being pulled out of a solenoid

The element in an incandescent light bulb that releases light energy is _____.

a thin tungsten filament

The Greeks studied charges using _____.

amber

Ampere showed that parallel wires carrying current in the same direction would _____ each other.

attract

A positively charged atom or group of atoms can be called a(n) _____.

cation

When you turn on a television, the electrical circuit _____.

closes

Which of the following factors influence the electrical resistance of a circuit?

conductivity of the material length of conducting wires diameter of conducting wires

Ocean water conducts electrical current because it contains _____.

electrolytes

The electricity that is delivered to our homes from regional generating stations moves over transmission lines that are _____.

high voltage and low current

As more resistors are added to a parallel circuit, the current _____

increases .

The unit of resistance is _____.

ohms

In a circuit, a battery is used to _____.

raise the potential of electrons

Electrostatic charges are created by _____.

stripping outer electrons from substances

The unit of electric potential or electromotive force is the _____.

volt