GCSE Physics- Electricity
The current in the circuit is direct current. What is meant by direct current? ANS: current that is always
in the same direction
Replacing one of the resistors with a resistor of higher value will.................... the reading on the
ammeter ANS: Decrease
Which one of the diagrams, X, Y or Z, shows the trace that would be seen on the oscilloscope?
Why? ANS: Y because it shows a direct current
What is the frequency of the a.c. mains electricity supply? ANS: 50Hz
To boil the water in the kettle, 2400 coulombs of charge pass through the heating element in 200
seconds.
Calculate the current flowing through the heating element and give the unit. ANS: 12 amps
What pattern links the amount of charge passing through the heating element and the time the kettle is
switched on? ANS: the charge is directly proportional to the time switched on for
In a series circuit with three resistors, and the voltage of the battery as 6V, what would be the voltage
through each resistor if all three of them are identical? ANS: 2V
The reading on ammeter A2 will be...........the reading on ammeter A1.
(same circuit as described above) ANS: Equal to
Symbol for diode vs LED ANS: This is the symbol for a diode, and it has arrows going away from it if it's
an LED
,The student started with one resistor and then added more identical resistors to the circuit.
Each time a resistor was added, the student closed the switch and took the ammeter reading.
The student used a total of 4 resistors.
Which variable did the student keep the same? ANS: Voltage of the power supply
A student wants to investigate how the current through a filament lamp affects its resistance. (a) Use
the circuit symbols in the boxes to draw a circuit diagram that she could use. ANS: battery, lamp and
ammeter connected in series with variable resistor
voltmeter in parallel with (filament) lamp
Describe how the student could use her circuit to investigate how the current through a filament lamp
affects its resistance. ANS: - ammeter used to measure current
- voltmeter used to measure potential difference
- resistance of variable resistor altered to change current in circuit or
change potential difference (across filament lamp)
- resistance (of filament lamp) calculated or R=V / I statement
- resistance calculated for a large enough range of different currents that would allow a valid conclusion
about the relationship to be made
Graph A- kind of directly proportional with some curves at beginning and end
Graph B- directly proportional
Graph C- constant horizontal with increase towards end ANS: Filament lamp
Resistor at constant temperature
Diode
, Describe how a student would use the circuit to take the readings necessary to determine the resistance
of resistor R. ANS: - Switch on
- Read both ammeter and voltmeter
- Adjust variable resistor to change the current
- Take further readings
- Draw graph
- Of V against I
- R= V/I
Explain why the student should open the switch after each reading ANS: Resistor would get hot if
current left on so its resistance would increase
The student told his teacher that the resistance of resistor R was 16 Ω. The teacher explained that the
resistors used could only have one of the
following values of resistance.
10 Ω 12 Ω 15 Ω 18 Ω 22 Ω
Suggest which of these resistors the student had used in his experiment. Give a reason for your answer.
ANS: 15 Ω
16 is nearer to that value than any other
The diagram shows a fuse. Describe the action of the fuse in a circuit. ANS: If the current is above 5
amps, the fuse melts and breaks the circuit
Calculate the resistance of the resistor labelled R. ANS: R = 12/0.10
total resistance = 120 ohms
The current in the circuit is direct current. What is meant by direct current? ANS: current that is always
in the same direction
Replacing one of the resistors with a resistor of higher value will.................... the reading on the
ammeter ANS: Decrease
Which one of the diagrams, X, Y or Z, shows the trace that would be seen on the oscilloscope?
Why? ANS: Y because it shows a direct current
What is the frequency of the a.c. mains electricity supply? ANS: 50Hz
To boil the water in the kettle, 2400 coulombs of charge pass through the heating element in 200
seconds.
Calculate the current flowing through the heating element and give the unit. ANS: 12 amps
What pattern links the amount of charge passing through the heating element and the time the kettle is
switched on? ANS: the charge is directly proportional to the time switched on for
In a series circuit with three resistors, and the voltage of the battery as 6V, what would be the voltage
through each resistor if all three of them are identical? ANS: 2V
The reading on ammeter A2 will be...........the reading on ammeter A1.
(same circuit as described above) ANS: Equal to
Symbol for diode vs LED ANS: This is the symbol for a diode, and it has arrows going away from it if it's
an LED
,The student started with one resistor and then added more identical resistors to the circuit.
Each time a resistor was added, the student closed the switch and took the ammeter reading.
The student used a total of 4 resistors.
Which variable did the student keep the same? ANS: Voltage of the power supply
A student wants to investigate how the current through a filament lamp affects its resistance. (a) Use
the circuit symbols in the boxes to draw a circuit diagram that she could use. ANS: battery, lamp and
ammeter connected in series with variable resistor
voltmeter in parallel with (filament) lamp
Describe how the student could use her circuit to investigate how the current through a filament lamp
affects its resistance. ANS: - ammeter used to measure current
- voltmeter used to measure potential difference
- resistance of variable resistor altered to change current in circuit or
change potential difference (across filament lamp)
- resistance (of filament lamp) calculated or R=V / I statement
- resistance calculated for a large enough range of different currents that would allow a valid conclusion
about the relationship to be made
Graph A- kind of directly proportional with some curves at beginning and end
Graph B- directly proportional
Graph C- constant horizontal with increase towards end ANS: Filament lamp
Resistor at constant temperature
Diode
, Describe how a student would use the circuit to take the readings necessary to determine the resistance
of resistor R. ANS: - Switch on
- Read both ammeter and voltmeter
- Adjust variable resistor to change the current
- Take further readings
- Draw graph
- Of V against I
- R= V/I
Explain why the student should open the switch after each reading ANS: Resistor would get hot if
current left on so its resistance would increase
The student told his teacher that the resistance of resistor R was 16 Ω. The teacher explained that the
resistors used could only have one of the
following values of resistance.
10 Ω 12 Ω 15 Ω 18 Ω 22 Ω
Suggest which of these resistors the student had used in his experiment. Give a reason for your answer.
ANS: 15 Ω
16 is nearer to that value than any other
The diagram shows a fuse. Describe the action of the fuse in a circuit. ANS: If the current is above 5
amps, the fuse melts and breaks the circuit
Calculate the resistance of the resistor labelled R. ANS: R = 12/0.10
total resistance = 120 ohms
