The diagram shows some electrical circuit symbols.
Which symbol represents a switch?
Which of the symbols in (a) represents a component that only allows current to flow in one direction?
Which of the symbols in (a) represents a component that can have its resistance varied by varying the length of wire?
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This question is about electrical components.
Draw a straight line from each electrical component to its correct symbol.
One has been done for you.
Which of the following is the correct symbol for a thermistor?
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A washing machine has an electric motor and an electric heater.
The resistance of the heater is 22 Ω.
The mains voltage is 230 V.
The washing machine is fitted with a fuse rated at 13 A.
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Which quantity is defined as the rate of flow of charge?
voltage
current
power
resistance
Which quantity is defined as the energy transferred per unit charge passed?
voltage
current
power
resistance
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The current in the wires of a circuit is a flow of particles.
What is the name of these particles?
electrons
positrons
protons
atoms
A student sets up an electrical circuit. The diagram shows part of this circuit.
Complete the circuit diagram by drawing circuit symbols for three devices so that the student can
The current in lamp A is 0.20 A. The voltage across lamp A is 6.0 V.
(2)
resistance = ......................................................Ω
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The diagram shows an electric circuit containing a fixed resistor and an LDR.
A student plans to use a voltmeter and an ammeter in his circuit.
How should the student connect the voltmeter and the ammeter within the circuit?
| Voltmeter | Ammeter | |
| A | in parallel across the power supply | in parallel across the LDR |
| B | in parallel across the LDR | in series with the LDR |
| C | in series with the power supply | in series with the LDR |
| D | in series with the LDR | in parallel across the LDR |
When the LDR is illuminated, its resistance is 150 Ω.
Show that the resistance of the fixed resistor is about 120 Ω.
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The diagram shows a heater coil and a resistor connected to a 12 V battery and an ammeter.
The ammeter reading is 1.2 A.
Resistors can be used as heating elements in the rear windows of cars.
The diagram shows two possible designs.
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The diagram shows a van der Graaff generator, a device that can reach extremely high voltages.
Calculate the energy transferred to an electron when it passes through a voltage of 180 kV.
Charge of an electron = 1.6 × 10–19 C
When the van der Graaff generator is fully charged, it stores 3.5 × 10–8 C of charge.
mean current = .................................................. unit .................
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The diagram shows a current-voltage graph for a resistor and for a lamp.
The voltage applied to the resistor is increased.
What is the effect on the resistance of the resistor?
resistance increases
resistance decreases
resistance increases and decreases
resistance stays the same
The voltage applied to the lamp is increased.
What is the effect on the resistance of the lamp?
resistance increases
resistance decreases
resistance increases and decreases
resistance stays the same
The p.d. across the lamp is 6.0 V.
resistance = ......................................................... Ω
The lamp and the resistor are connected in parallel to a 6.0 V supply.
Calculate the current from the supply.
(2)
current = ......................................................... A
The lamp and the resistor are connected in series to another power supply. The current in the circuit is 4.0 A.
Calculate the total voltage across the lamp and the resistor.
voltage = ......................................................... V
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A light-emitting diode (LED) is a diode that emits light when there is a current in it.
Draw a circuit diagram showing an LED, connected so that it is lit, in series with a battery and a fixed resistor.
The voltage across the LED when lit is 3.1 V and the current in the LED is 0.030 A.
resistance = ......................................................... Ω
The diagram shows a power supply with a voltage of 12 V connected in series with a lamp and a heater.
The voltage across the lamp is 3.2 V and the current in the lamp is 1.5 A.
resistance = ......................................................... Ω
power = ......................................................... W
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The current in a metalic conductor is a flow of
negatively charged electrons
negatively charged protons
positively charged electrons
positively charged protons
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The photograph shows a solar-powered battery charger connected to a mobile phone.
When the battery charger is used, it transfers light energy from the Sun to the battery of the mobile phone.
It takes 3.5 hours to recharge the battery fully. The average current supplied by the charger is 400 mA.
If the charger is moved into the shade, the output power decreases. The voltage across the charger stays the same.
Explain how moving the charger into the shade affects the time needed to recharge the battery fully.
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An electric vehicle has a rechargeable battery.
The battery is recharged by connecting it to a charging station.
©Epattlomer
The battery voltage is 385 V.
Charging takes 110 minutes and causes a total charge of 180 000 C to pass through the battery.
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A student investigates the resistance of a lamp.
The student uses a circuit that contains an ammeter, a battery, a lamp and a voltmeter to determine the resistance of the lamp.
Draw a circuit diagram to show how he should connect the apparatus.
State the relationship between voltage, current and resistance.
The student obtains this graph for a filament lamp.
Calculate the resistance of the lamp when the voltage is 6.0 V.
Give the unit.
The student reverses the battery connections and then repeats his measurements.
On the axes below, sketch the graph that he would obtain.
Part of the graph has been done for you.
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A student is investigating the variation of resistance and temperature in a thermistor. The diagram shows part of the circuit the student intends to use.
Complete the circuit diagram to show how the student should connect the apparatus, including a voltmeter and an ammeter.
The student chooses a fixed resistor with a resistance of 5 kΩ. The reading on the ammeter is 0.8 mA.
The manufacturer's guide states that the thermistor has a resistance of 12 kΩ at room temperature.
The student wants to confirm the accuracy of this value before starting the investigation.
At room temperature, the voltmeter shows a reading of 8 V.
Determine if this reading is consistent with the manufacturer's value of resistance.
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