Download Chaper 21 flashcards

Chaper 21 flashcards
1) The force a magnet exerts on another magnet is a (electrical, gravitational, magnetic)force.
2) Like poles repel each other and opposite poles attract each other is a statement about (electrical, gravitational,
magnetic) forces
3) As distance increases between 2 magnets, the magnetic forces (stays the same, increases, decreases)
4) The Earth’s magnetic poles are the areas where the magnetic fields are (the same as the geographic poles, the
weakest, the strongest)
5) If you break a magnet in half, each half (becomes a magnet with 2 poles, becomes unmagnetized, contains
only 1 magnetic pole)
6) A ferromagnetic material that has domains that remain aligned for a long period of time is called a
(permanent magnet, temporary magnet, neutral object)
7) A magnetic field is created by (air resistance, moving electric charges, gravity)
8) A coil of wire that is carrying a current and produces a magnetic field is a (solenoid, galvanometer, electric
motor)
9) A soft iron is used for the cores of an electromagnet because it is (a permanent magnet, easily magnetized, is
difficult to magnetized)
10) In an electric motor the axles spin because (the electromagnet loses its magnetism, mechanical energy is
converted into electrical energy, the magnetic field is reversed)
11) To increase the voltage in a coil, you move the magnet inside the coil of wire (slower, more rapidly,
stationary)
12) The process of generating an electric current by moving an electrical conductor relative to a magnetic field
is called electromagnetic (contact, friction, induction)
13) Mechanical energy to electrical energy is called a (electromagnet, transformer, generator)
14) Current in power lines must pass through a (electromagnet, transformer, generator) before coming into your
home.
15) Fossil fuels are used to heat water that (turns into steam that spins a turbine to generate electricity, causes an
electric motor to produce current, spins a magnet inside an electric motor)
16) The region where a magnet’s force is the strongest is at the (poles, center, everywhere)
17) Regions having large numbers of atoms with aligned magnetic fields are called (nails, poles, magnetic
domains).
18) The type of generator that large power plants use in the US is (AC, DC, PC) generators
19) Voltage can be induced in a conductor by changing a magnetic field is known as (Ohm’s Farraday’s,
Orsted’s) law.
20) Moving a magnet through a wire can produce a (gravitational force, magnetic force, current) in the coil.
21) A (generator, electric motor, transformer) converts electrical energy into mechanical energy.
22) A (step-down, step-up, step-potential) transformer increases the current and dectreasses voltage in the
output circuit
23) The strength of a (transformer, electromagnet, permanent magnet) depends on the current, number of coils
and type of core.