39 terms

Magnetism and Electricity Review

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Magnetic Force
The force a magnet exerts on another magnet, on iron or a similar metal, or on moving charges is a?
Like poles repel and opposite poles attract
Which of the following describes the interaction between magnetic poles?
The magnetic force decreases
How does the magnetic force exerted by a magnetchange as the distance between two magnets increases?
Field lines begin near the magnet's north pole and extend toward its south pole.
Which statement describes magnetic field lines at the north pole and south pole of a bar magnet?
Magnetosphere
What is the name of the area surrounding earth that is influenced by earth's magnetic field?
They are the areas where earth's magnetic field is strongest.
Which of the following statments is true about earth's magnetic poles?
A magnetic domain
A region that has a large number of atoms whose magnetic fields are lined up parallel to a magnet's field is?
Becomes a bar magnet with two poles
If you break a bar magnet in half, each half does what?
A permanent magnet
A ferromagnetic material that has domains that remain aligned for a long period of time is called?
Heath the magnet up, and strike the magnet with a heavy blow.
How can a permanent magnet be demangetized?
Moving electric charges.
What creates a magnetic field?
It is easily magnetized.
Which of the following is the reason "soft" iron is used for the cores of electromagnets?
The magnetic field reverses direction.
In an electric motor, periodically changing the direction of current in the electromagnet can cause the axle to spin because what?
Electromagnetic Induction
The process of generating an electric current by moving an electrical conductor relative to a magnetic field is called?
Generator
A device that changes mechanical energy to electrical energy by rotating a coil of wire through a magnetic field is called a?
Negatively charged ion.
If an atom gains electrons, it becomes a?
Amount of charge that produced the field and distance from the charge.
The strength of an electric field depends on the?
The quantity of charge involved and how far apart the charges are.
What do electric forces between charges depend on?
Friction
Walking across a carpet is an example of charge be transferred by what?
Induction
If a neutral metal comb is held near an object with a negative charge, the comb with become charged by what?
Direct Current
What type of current is produced by a battery?
Alternating Current.
What type of current is used in your school the most?
Electrons tightly bound to its atoms.
An electrical insulator has?
Thickness, Temperature, and length
Resistance is affected by a material's what?
Increasing its thickness.
Which of the following would reduce the resistance of a metal wire?
Potential difference
What is the difference in electrical potential energy between two places in an electric field?
Potential difference and voltage drop
Which of the following is maintained across the terminals of a battery?
120 V
The current in a hair dryer measures 15.0 Amps. The resistance of the hair dry is 8 Ohms. What is the voltage?
V=I x R
Which of the following represents Ohm's law?
One
How many paths through which charge can flow would be shown in a circuit diagram of a series circuit?
Parallel Circuits
Most of the circuits in your home are?
Watt
What is the unit of electric power?
Dividing the power by the voltage.
If you know the power rating of an appliance and the voltage of the line it is attached to, you can calculate the current, the appliance uses by?
An electrical conductor
Which of the following materials allows charges to flow easily?
Circuit breaker, fuse, ground-fault circuit interrupter.
Which of the following provides electrical safety?
Solenoid
A coil of wire that is carrying a current and produces a magnetic field is a?
Galvanometer
The device that measures current in a wire by using the deflection of an electromagnet in an external magnetic field is a?
Moves a pointer along a numbered scale in response to a current
The electromagnet in a galvanometer.....?
Move the magnet inside the coil of wire more rapidly.
Moving a magnet inside a coil of wire will induce a voltage in the coil. How can the voltage in the coil be increase?