5.1 - 5.2
An electromagnet creates a magnetic force :
A. as long as a power source is connected.
B. only with a battery power source.
C. only with an alternating current power source.
A. as long as a power source is connected
Which device is used to detect and measure small electric currents?
A. voltmeter
B. galvanometer
C. Ohmmeter
D. none of these
B. galvanometer
How much power does the average hair dryer use??
A. 20w
B. 75w
C. 750w
D. 1,200w
D. 1,200
What can iron filings be used to show?
A. magnetic field
B. electric field
C. gravitational field
D. none of these
A. magnetic field
The defention of Galvanometer:
A device for detecting or measuring small electric currents.
The flow of charged particles is called:
A. an electric current
B. a voltage source
C. a resistor
D. an inductor
A. an electric current
A dc battery provides:
A. potential energy
B. an insulator to a circuit.
C. always can be recharged
D. none of these
A. potential energy
What is the force between two electrons?
A. unbalanced
B. neutral
C. attractive
D. repulsive
D. repulsive
Why does the needle of a compass point to magnetic north?
A. earth's north pole is the strongest.
B. earth's north pole is the closest.
C. only the north pole attracts compasses.
D. the compasses needle aligns itself with Earth's magnetic field.
D. the compasses needle aligns itself with Earth's magnetic field.
The defention of Magnetic field:
The strength and directon of the magnetic force a magnet exerts at each point in space; the magnetic feild grows weaker as distance from the magnet inceases.
As a voltage of the source powering an electromagnet increase, the magnetic force generated by the electromagnet:
A. decreases
B. increases
C. must remain the same
B. increases
A single path for current is present in which type of circuit?
A. series, only
B. parallel, only
C. both series and parallel
D. neither series nor parallel
A. series, only
What property of a wire increases when it is made thinner?
A. resistance
B. voltage
C. current
D. charge
A. resistance
What will the north poles of two bar magnets do when brought together?
A. attract
B. create an electric current
C. repel
D. not interact
C. repel
The defention of Electro-magnetism:
The relationships between magnetsm and electricity.
Like charges ________; unlike charges __________.
A. attract; repel
B. attract; attract
C. repel; repel
D. repel ; attract
D. repel; attract
A generator transforms:
A. mechanical energy into electrical energy.
B. mechanical energy into heat.
C. electrical energy to mechanical energy.
D. heat into mechanical energy.
A. mechanical energy into electrical energy.
Why is severe electric shock dangerous?
A. it can stop a heart from beating
B. it can cause burns
C. It can interfere with breathing
D. all of the above is true.
D. all of the above is true
How many poles do all magnets have?
A. one
B. two
C. three
D. one or two
B. two
The defention of Series Circuit:
A closed circiut in which all pats are connected end to provide a single path for the current.
A bar magnet with a north and south pole is cut in half. The new smaller magnets will:
A. consists of one having a north pole only and the other having a south pole only.
B. is not magnetic
C. consist of two magnets, both with a north and south pole like the original magnet.
C. consist of two magnets, both with a north and south pole like the original magnet.
Batteries produce ____; generators make____.
A. ac; dc
B. ac; ac
C. dc; dc
D. dc; ac
D. dc;ac
What unit of electrical energy is sold by electric companies?
A. ampere
B. ohm
C. volt
D. kilowatt-hour
D. kilowatt-hour
When a current-carrying wire is wrapped around an iron core, what can it create?
A. an aurora
B. a magnet
C. a generator
D. a motor
B. a magnet
The defention of Parallel Circuit:
A closed circuit in which the current divides into two or more paths before recombining to complete the circuit.