Electricity

Question 1

the best electrical conductors are…

Answer 1

metals

Question 2

the best electrical insulators are…

Answer 2

air, glass, plastic, wood

Question 3

lighting is a buildup of…

Answer 3

static electricity

Question 4

device that detects the presence of electric charges

Answer 4

electroscope

Question 5

positively charged particles are called

Answer 5

protons

Question 6

particles with no charge are called

Answer 6

neutrons

Question 7

negatively charged particles are called

Answer 7

electrons

Question 8

an electric current is

Answer 8

the net movement of electric charges in a single direction

Question 9

true or false: constant random motion of electrons stops when a current flows

Answer 9

false: electrons are always in constant random motion

Question 10

electric current is measured in

Answer 10

amperes / amps

Question 11

voltage difference is measured in

Answer 11

volts

Question 12

true or false: charges flow from a high voltage to a low voltage

Answer 12

true

Question 13

a voltage difference is

Answer 13

the force that causes electric charges to flow

Question 14

a circuit is

Answer 14

a closed path an electric current follows

Question 15

three types of batteries are?

Answer 15

dry-cell, wet-cell, lead-acid

Question 16

which battery has liquid in it?

Answer 16

wet-cell

Question 17

which battery is used in your car?

Answer 17

lead-acid

Question 18

which battery has a paste?

Answer 18

dry-cell

Question 19

dry-cell batteries have what two elements?

Answer 19

carbon rod (positive), and zinc (negative)

Question 20

resistance is

Answer 20

the tendency of a material to oppose the flow of electrons

Question 21

resistance is measured in

Answer 21

ohms ( Ω )

Question 22

electric resistance usually increases when

Answer 22

the temperature of that object increases

Question 23

resistance also increases when the wire length

Answer 23

increases

Question 24

which has more electrical resistance: conductors or insulators?

Answer 24

insulators

Question 25

resistance increases when wire thickness/diameter

Answer 25

decreases (thinner wire = more resistance)

Question 26

ohms law states that

Answer 26

current (amps) = voltage difference (volts) / resistance (ohms)

V = C x R

Question 27

a simple circuit needs what three things

Answer 27

voltage difference, current, resistance

Question 28

current only has one loop to flow through. current the same voltage varies

Answer 28

series circuit

Question 29

2 or more branches for current to move through. voltage the same current varies

Answer 29

parallel circuit

Question 30

fuse

Answer 30

small piece of metal that melts if current becomes too high, stopping the flow of current. (think Christmas lights)

Question 31

circuit breaker

Answer 31

prevents circuit from overheating(causing fire). metal that bends when current in it is so large it gets hot. can be reset (house)