Topic 9 Electricity & circuits Flashcards
1 What word describes materials that electricity will pass through?
conductors
2 What word describes materials that electricity cannot pass through?
insulators
3 What components do you need to make a circuit that would make a small torch bulb light up?
battery, connecting wires, lamp; switch is optional
4 What are the two terminals of an electric cell labelled as?
plus and minus
5 In an electric circuit with a battery, which of these materials will conduct: copper, wood, salty water?
copper and salty water
6 Which of these materials are insulators: plastic, metal, air?
plastic and air
7 What component is used to measure current?
ammeter
8 What name is given to the negatively charged subatomic particles that cause an electric current?
electrons
9 Is mains voltage about 15 times, 150 times or 1500 times bigger than the voltage from a battery?
about 150 times
10 If you connect some cells together in series, what is formed?
a battery
11 What is the name of a circuit with one path around it and no branches?
a series circuit
12 What is the name given to a circuit with components in different branches?
a parallel circuit
13 What is the circuit symbol for a lamp?
circle with a cross in it
14 What is the circuit symbol for a cell?
two vertical lines, one longer than the other
15 How can you tell which is the negative terminal of a cell from the circuit symbol?
It is the shorter line.
16 What is the difference between conventional current and the flow of electrons?
Electrons flow from the negative terminal of a cell to the positive terminal, conventional current flows the other way.
17 What unit is current measured in?
amps/amperes
18 What is another term for potential difference?
voltage
19 Which component is used to measure electric current?
an ammeter
20 What are the units for current?
amps or amperes
21 What two conditions are needed to give a current in a circuit?
closed circuit and potential difference
22 Is an ammeter connected in parallel or in series with a component?
series
23 A series circuit has two lamps. When the current through one lamp is 2A, what is the current through the other lamp?
2A
24 A parallel circuit has two lamps in parallel. When the current through each lamp is 2A, what is the current from the battery?
4A
25 Which component is used to measure potential difference?
a voltmeter
26 What are the units for potential difference?
volts
27 Current can be described as the rate of flow of charge. In a metal, what are the charged particles that flow?
electrons
28 In a circuit, energy is transferred to a charge. Where is this energy transferred from?
cell/battery/power supply
29 What is an electric current?
a flow of charge
30 State the unit and the symbol for current.
amp/ampere, A
31 State the unit and the symbol for charge.
coulomb, C
32 Write down the equation relating the total charge that flows to current and time.
Q = I x t
33 State the unit and the symbol for potential difference.
volt, V