Science And Inventions 1

Front 1

Strip electrons from an atom and the atom becomes

Back 1

positive ion

Front 2

To say that electric charge is conserved means that no case has ever been found where the

Back 2

net charge has been created or destroyed

Front 3

A conductor differs from an insulator in that a conductor

Back 3

has none of these:
has more electrons than protons.
has more protons than electrons.
has faster moving molecules.
has more energy than an insulator.

Front 4

Charge carriers in a metal are electrons rather than protons because electrons are

Back 4

loosely bound

Front 5

Electrons are made to flow in a wire when there is

Back 5

a potential difference across its ends.

Front 6

A wire that carries an electric current

Back 6

may be electrically charged.

Front 7

which is correct?
a.Resistance flows though an open circuit.
b. Charge flows in a closed circuit.
c.Current is the primary cause of voltage.
d. Voltage flows through an open or a closed circuit.

Back 7

b. Charge flows in a closed circuit.

Front 8

A wire carrying a current is normally charged

Back 8

not at all

Front 9

The primary source of electrons in an ordinary electrical circuit is

Back 9

the electrical circuit itself.

Front 10

Alternating current is normally produced by a

Back 10

generator

Front 11

In a simple circuit containing a bulb, energy is given to the moving charges by

Back 11

a generator

Front 12

A positive ion has more

Back 12

protons than electrons.

Front 13

Moving electric charges will interact with

Back 13

an electric field or a magnetic field.

Front 14

Like kinds of magnetic poles repel while unlike kinds of magnetic poles

Back 14

attract

Front 15

An iron nail is more strongly attracted to the

Back 15

north or south pole - no difference really.

Front 16

Magnetic field lines about a current-carrying wire

Back 16

extend radially from the wire.
circle the wire in closed loops.
Choices A and B are both correct.
None of the above choices are correct.

Front 17

if we think of the Earth as a magnet, its north (-seeking) pole is nearest

Back 17

Australia

Front 18

Which pole of a compass needle points to a south pole of a magnet?

Back 18

north pole

Front 19

Outside a magnet, magnetic field lines are conventionally drawn from

Back 19

north to south

Front 20

When a bar magnet is broken in two, each half is

Back 20

as magnetic as the original magnet.

Front 21

Thrust a magnet into a coil of wire and the coil

Back 21

has a current in it

Front 22

in an electrically neutral atom the number of protons in the nucleus is equal to the number of

Back 22

electrons that surround the nucleus.

Front 23

to say that electric charge is quantized is to say that the charge on an object

Back 23

is a whole-number multiple of the charge of one electron

Front 24

To say that electric charge is conserved is to say that electric charge

Back 24

can be neither created nor destroyed.

Front 25

Rub electrons from your hair with a comb and the comb becomes

Back 25

negatively charged.

Front 26

An electron and a proton

Back 26

attract each other.

Front 27

If you comb your hair and the comb becomes positively charged, then your hair become

Back 27

negatively charged.

Front 28

A balloon will stick to a wooden wall if the balloon is charged

Back 28

either positively or negatively.

Front 29

The magnetic field strength inside a current-carrying coil will be greater if the coil encloses a

Back 29

rod of iron

Front 30

A device that transforms electrical energy to mechanical energy is a

Back 30

motor

Front 31

When a bar magnet is thrust into a coil of copper wire, the coil tends to

Back 31

repel the magnet as it enters.

Front 32

A device that transforms mechanical energy into electrical energy is a

Back 32

generator

Front 33

Electromagnetic induction occurs in a coil when there is a change in

Back 33

magnetic field intensity in the coil.

Front 34

Magnetic field lines about a current-carrying wire

Back 34

circle the wire in closed loops.