ELECTRIC CIRCUITS

Question 1

when do charges move

Answer 1

when the ends of a conductor are connected to an emf and a closed circuit is formed

Question 2

what is the unit of charge

Answer 2

(C) coulomb

Question 3

current strength

Answer 3

is the amount of charge moving through a certain point in a circuit in one second

Question 4

current

Answer 4

the rate of flow of electrical charge

Question 5

symbol and unit of measurement for current

Answer 5

1. I

2. ampere(A)

Question 6

potential difference

Answer 6

potential difference is the difference in electrical potential energy per unit charge between two points in a circuit

Question 7

symbol and unit of measurement for potential difference

Answer 7

1. V

2. volt(V)

Question 8

EMF

Answer 8

the emf of a battery is the total amount of energy that a battery can supply per unit charge and is measured in volts

Question 9

external potential difference

Answer 9

is the work done in moving charges through the circuit to provide energy to resistors, rheostats and light bulbs and is measured with a voltmeter which is connected across a battery when the current is flowing therefore when work is being done in the circuit(switch is closed)

Question 10

resistance

Answer 10

electrical resistance is the opposition a conductor offers to a flow of charge

Question 11

factors that determine a conductors resistance

Answer 11

1. type of conductor(better=less resistance)
2. length of conductor(longer=more resistance)
3. thickness of conductor(thicker=less resistance)
4. temperature(higher=greater resistance)

Question 12

symbol and unit of measurement for resistance

Answer 12

1. R

2. ohm

Question 13

ohms law

Answer 13

the potential difference across the resistor is directly proportional to the current flowing through a resistor, provided the temperature remain constant

Question 14

ohmic conductor

Answer 14

obeys ohms law for all values of current and potential difference

Question 15

example of ohmic conductors

Answer 15

nichrome wire

Question 16

non-ohmic conductors

Answer 16

does not obey ohms law

Question 17

example of non-ohmic conductors

Answer 17

light bulb, electrolyte solution, LED, thermistor

Question 18

what is energy converted to in an electric circuit

Answer 18

1. heat energy in a resistor

2. heat and light energy in a light bulb

Question 19

symbol and unit of measurement for energy

Answer 19

1. W

2. joule(J)

Question 20

power

Answer 20

the rate at which work is done or energy is transferred

Question 21

symbol and unit of measurement for power

Answer 21

1. P

2. watt(W)

Question 22

what is energy that is converted equal to

Answer 22

is equal to the work done in moving electrons through a resistor

Question 23

how can 1 save electricity

Answer 23

1. switch off geysers during the day
2. switch off all devices at wall sockets
3. do not turn stove plates up to the highest setting
4. close doors and windows when you switch heater on