Science 9 - Chapter 8 Test

Question 1

electric potential energy

Answer 1

electric energy stored in a battery. electrons have stored energy and the ability to do work after they leave the battery.

Question 2

electrochemical cells

Answer 2

convert chemical energy into electrical energy stored in charges. commonly called cells or batteries.

Question 3

electrodes

Answer 3

batteries have two terminals called electrodes. usually made up of two different metals (but can be metal and another material) in an electrolyte.

Question 4

electrolyte

Answer 4

substance that conducts electricity. dry cells = moist paste. wet cells = fluid.

Question 5

energy

Answer 5

the ability to do work

Question 6

potential difference

Answer 6

change in potential energy per coulomb of charge

Question 7

volt

Answer 7

Unit of measurement for voltage

Question 8

voltage

Answer 8

common name for electric potential difference

Question 9

amperes

Answer 9

unit for measuring electric current (one coulomb of charge passing a given point per second)

Question 10

circuit diagrams

Answer 10

drawn to represent electric circuits

Question 11

current electricity

Answer 11

flow of charged particles in a complete circuit

Question 12

electric circuit

Answer 12

complete pathway that allows electrons to flow. circuit must contain at least one source of voltage. electric potential energy transformed into other forms of energy

Question 13

battery

Answer 13

combination of electrochemical cells connected (or a single electrochemical cell.) chemical energy separates the negative and positive charges.

Question 14

terminals

Answer 14

end points where we make a connection. extra electrons accumulate on one of the battery terminals making it negatively charged. other terminal has lost these electrons and is therefore positively charged.

Question 15

kinetic energy

Answer 15

energy a moving object has because of its motion.

Question 16

potential energy

Answer 16

energy stored in a object

Question 17

voltmeter

Answer 17

device that measures the amount of potential energy difference between two locations of charge separation. when you place the connecting wires of a voltmeter across the + and - terminals of a battery, voltmeter displays battery voltage.

Question 18

groups of batteries

Answer 18

dry and wet cells

Question 19

dry cells

Answer 19

batteries in device like flashlights, portable CD players, and watches

Question 20

wet cells

Answer 20

commonly used in cars, motorcycles, and electric wheelchairs

Question 21

sources of electric energy

Answer 21

friction, piezoelectric crystals, photo-electrochemical cells, thermocouples, generators

Question 22

ammeter

Answer 22

device used to measure current

Question 23

electric load

Answer 23

any device that transforms electrical energy into other forms of energy

Question 24

four basic types of circuit components

Answer 24

source: source of electrical energy
conductor: the wire through which electric current flows
load: device that transforms electrical energy into other forms of energy
switch: a device that can turn the circuit on or off by closing or opening the circuit

Question 25

difference between static and current electricity

Answer 25

static: charge remains unmoving on insulator current: charge flows continually through circuit

Question 26

electric current

Answer 26

charge flowing in an conductor. defined as amount of charge passing a point in a conductor every second.

Question 27

ohms

Answer 27

measurement of resistance (Ω)

Question 28

resistors

Answer 28

electrical components used in circuits to decrease current and convert electrical energy into other forms of energy

Question 29

resistance

Answer 29

slows down flow of electrons and converts electrical energy into other forms of energy. measured in ohms. (Ω)

Question 30

ohm's law

Answer 30

Resistance (R) = V/I Voltage (V) = I*R Current (I) = V/R

Question 31

milli (m) kilo (k) mega (m) micro (µ)

Answer 31

``` one thousandth (1000 milli "things" in a thing) one thousand (1000 "things" in a kilo "thing") one million (1000000 "things" in a mega "thing") one millionth (1000000 micro "things" in a "thing") ```

Question 32

Difference between electron flow and current flow

Answer 32

In electron flow electrons are negative and flow from negative to positive. 'Conventional' current flow is from positive to negative. This is because early researchers in electricity thought electricity flowed from positive to negative, which is why they called them that in the first place.