Electric circuits

Each of the four lamps is labelled $240\,\text{V}$. In which circuit will all four lamps shine with normal brightness?

Feb/March 2016

The diagram illustrates a $40\,\Omega$ resistor and a $60\,\Omega$ resistor arranged in parallel. What is the combined resistance between points P and Q?

Feb/March 2016

The diagram illustrates a potential divider connected to voltmeters P and Q. The resistance of the variable resistor is reduced. Which row indicates the change in the reading on each voltmeter?

Feb/March 2016

Which circuit shows the direction of the conventional current $I$ and the movement of electrons?

Feb/March 2016

Each of the four lamps is marked $240\,\text{V}$. In which circuit do all four lamps shine at normal brightness?

Feb/March 2016

A battery charger is connected to a $230\,\text{V}$ a.c. mains supply. It is then used to charge a $6.0\,\text{V}$ d.c. battery. Inside the charger are diodes and a transformer. What is the purpose of these components?

Feb/March 2016

The diagram illustrates a potential divider linked to two voltmeters P and Q. The resistance of the variable resistor is reduced. Which row shows what happens to the reading on each voltmeter?

Feb/March 2016

On Fig. 11.1, finish drawing the missing circuit symbols.

Feb/March 2016

State the name of the logic gate shown.

Feb/March 2016

Fig. 8.1 illustrates 3 lamps together with a fuse linked to a power supply. The e.m.f. of the supply is $220\,\text{V}$. Each lamp is marked $220\,\text{V}, 40\,\text{W}$. The fuse is rated at $2.0\,\text{A}$.

Feb/March 2016

In the circuits shown, every resistor has a resistance of $1.0\,\Omega$. Which circuit has the largest resistance?

Feb/March 2017

The diagram depicts an electric circuit. The brightness of the light falling on the light-dependent resistor (LDR) increases. What happens to the resistance of the LDR, the current in the fixed resistor and the reading on the voltmeter?

Feb/March 2017

The diagram illustrates two connected circuits used to decide when a bell is activated. The conditions are changed, and just one combination of conditions makes the bell sound. Which combination makes the bell sound?

Feb/March 2017

Four circuits have been arranged. In which circuit does the ammeter indicate the largest reading?

Feb/March 2017

The diagram illustrates an electric circuit. The light incident on the light-dependent resistor (LDR) becomes brighter. What happens to the resistance of the LDR, the current in the fixed resistor and the voltmeter reading?

Feb/March 2017

The diagram shows two linked circuits used to control the point at which a bell is activated. The conditions are changed, and only one pair of conditions makes the bell ring. Which pair makes the bell ring?

Feb/March 2017

A truth table for a logic gate is shown. Which kind of logic gate does it represent?

Feb/March 2017

Fig. 9.1 is a graph showing current plotted against potential difference (p.d.) for a filament lamp.

Feb/March 2017

A student assembles the circuit shown in order to measure three quantities. 1 the current in the circuit 2 the electromotive force (e.m.f.) of the cell 3 the potential difference across the lamp How many ammeters and how many voltmeters are required?

Feb/March 2018

The diagram represents a circuit with a cell, an ammeter, a lamp and a variable resistor. The resistance of the variable resistor is increased. What effect does this have on the ammeter reading, and what effect does it have on the brightness of the lamp?

Feb/March 2018

Diagram 1 shows two identical lamps arranged in series with a cell. Diagram 2 shows the same two lamps arranged in parallel with an identical cell. Which statement is correct?

Feb/March 2018

A circuit includes four ammeters and three resistors of different values. Which ammeter indicates the greatest reading?

Feb/March 2018

The diagram illustrates a circuit. Switch S is closed. Which lamps will light up?

Feb/March 2018

A circuit includes four ammeters and three resistors of different values. Which ammeter gives the greatest reading?

Feb/March 2018

The diagrams illustrate pairs of circuits that include logic gates. In which diagram does the lower circuit in the pair not operate in the same manner as the upper circuit?

Feb/March 2018

A student builds an electrical circuit and sketches part of the circuit diagram, as shown in Fig. 8.1. The diagram includes a power supply, lamp A, lamp B and connecting wires.

Feb/March 2018

Fig. 9.1 presents current-potential difference graphs for a resistor and a lamp.

Feb/March 2018

Which of the following statements about a voltmeter is correct?

Feb/March 2019

A student assembles a circuit with a battery made up of two cells and three lamps, as shown. Which circuit diagram represents this arrangement?

Feb/March 2019

The diagrams illustrate different resistor arrangements. Which arrangement has the lowest total resistance?

Feb/March 2019

The diagram illustrates a potential divider circuit. The resistance of the variable resistor is made larger. Which row shows the effect on the reading on voltmeter P and on voltmeter Q?

Feb/March 2019

The current in a kettle is $10\,\text{A}$, and the kettle is safeguarded by a $13\,\text{A}$ fuse. The owner of the kettle changes the $13\,\text{A}$ fuse to a $3\,\text{A}$ fuse. What occurs when the kettle is turned on?

Feb/March 2019

A student builds a circuit with a battery made of two cells and three lamps, as shown. Which circuit diagram represents this arrangement?

Feb/March 2019

In which circuit does the lamp illuminate?

Feb/March 2019

Every potential divider is connected into a circuit together with a power supply. Which potential divider causes the potential difference across component Y to increase as the light intensity increases?

Feb/March 2019

The logic-gate arrangement shown has two inputs and one output. Which truth table shows the operation of this gate combination?

Feb/March 2019

Fig. 9.1 and Fig. 9.2 each illustrate an electrical circuit. In both circuits, two lamps are linked to an electrical supply.

Feb/March 2019

A student wants to find the resistance of resistor $R$. She sets up a circuit that contains a voltmeter and an ammeter. Which circuit should be used?

Feb/March 2020

The diagram depicts a battery joined to two resistors. Three ammeters $M_1$, $M_2$ and $M_3$ are included in the circuit. Ammeter $M_1$ shows $1.0\,\text{A}$. What readings do $M_2$ and $M_3$ show?

Feb/March 2020

The lamps in the circuit are arranged in parallel. What benefit does this arrangement have?

Feb/March 2020

The diagram illustrates a relay used to switch a buzzer. What is the function of the circuit?

Feb/March 2020

A student wants to measure the resistance of resistor R. She sets up a circuit with both a voltmeter and an ammeter. Which circuit should be used?

Feb/March 2020

The diagram presents a battery linked to two resistors. Three ammeters $M_1$, $M_2$ and $M_3$ are placed in the circuit. Ammeter $M_1$ shows $1.0\,\text{A}$. What readings do $M_2$ and $M_3$ show?

Feb/March 2020

A cell is linked to a parallel arrangement of a $2.0\,\Omega$ resistor and a $4.0\,\Omega$ resistor. The current through the $4.0\,\Omega$ resistor is $1.0\,\text{A}$. What current flows in the cell?

Feb/March 2020

The two inputs to a NAND gate are connected together. Which truth table shows how this gate works?

Feb/March 2020

Fig. 11.1 presents lamps connected in series, while Fig. 11.2 presents lamps connected in parallel. All the lamps are identical 6.0 V lamps. Each circuit contains three ammeters A1, A2 and A3.

Feb/March 2020

Fig. 4.1 illustrates an electric circuit. Energy is transferred from the battery to the filament lamp by an electric current.

Feb/March 2020

Fig. 8.1 depicts a circuit. The lamp’s resistance is 3.0 Ω, and line XY is a uniform resistance wire with resistance 6.0 Ω.

Feb/March 2020

State the name of the logic gate represented by the symbol in Fig. 9.1.

Feb/March 2020

A piece of metal wire is acting as a resistor in a circuit. Which alteration to the wire would cause the current in the circuit to increase?

Feb/March 2021

The diagram represents a circuit made up of a power supply, a lamp and a motor. Three ammeters are used to measure the current at different positions in the circuit. The ammeter readings are $I_1$, $I_2$ and $I_3$. Which statement about the ammeter readings is correct?

Feb/March 2021

A student sets up a circuit to act as a dimmer switch for a lamp. What occurs to the lamp’s brightness and the potential difference (p.d.) across the lamp when the slider is moved from X to Y?

Feb/March 2021

A resistor with resistance $R$ carries a current $I$ for a time $t$. The potential difference across the resistor is $V$. Which equation gives the energy $E$ transferred by the resistor?

Feb/March 2021

A resistor $R$ is arranged in parallel with an $8.0\,\Omega$ resistor. The combined resistance of the two is $4.0\,\Omega$. What resistance does resistor $R$ have?

Feb/March 2021

A student sets up a circuit to act as a dimmer switch for a lamp. What happens to the lamp’s brightness and to the potential difference (p.d.) across the lamp when the slider is moved from $X$ to $Y$?

Feb/March 2021

The circuit diagram shown has two gates. Which truth table represents how the circuit works?

Feb/March 2021

Fig. 9.1 displays an electric circuit. The labelled components are: buzzer; ammeter (A); voltmeter (V); thermistor.

Feb/March 2021

Define electromotive force (e.m.f.) in words.

Feb/March 2021

Give the truth table for an OR gate.

Feb/March 2021

The diagram illustrates a circuit. Which energy transfers take place?

Feb/March 2023

X, Y and Z are lamps. In which of these lamps does a current flow?

Feb/March 2023

The diagram illustrates a circuit. Which alteration makes the bulb in the circuit brighter?

Feb/March 2023

The diagram illustrates a section of a circuit. What is the total resistance of the resistors?

Feb/March 2023

The diagram illustrates a circuit containing two resistors and a battery. The voltmeter shows $6.0\,\text{V}$. Determine the potential difference across the $30\,\Omega$ resistor.

Feb/March 2023

Define potential difference (p.d.) in words.

Feb/March 2023

The diagram represents a circuit with two identical lamps and three ammeters. Ammeter 1 reads $0.30\,\text{A}$. Which row shows possible values for the currents in ammeters 2 and 3?

Feb/March 2024

In which circuit do both lamps come on?

Feb/March 2024

A student assembles the electrical circuit illustrated in Fig. 9.1.

Feb/March 2024

Draw the circuit symbol that represents a potential divider.

Feb/March 2024

Which circuit includes a thermistor and a heater?

Feb/March 2025

A resistor with resistance $R$ is connected to a battery of electromotive force (e.m.f.) $V$. A current $I$ flows through the resistor. The resistor dissipates power $P$. Over a time $t$, the energy transferred is $E$. Which expression is the correct one?

Feb/March 2025

Four identical resistors are arranged with a battery as illustrated. Each resistor has a resistance of $120\,\Omega$. Resistor $R_4$ is taken out. What effect does the removal of this resistor have on the circuit’s effective resistance?

Feb/March 2025

The resistors in the circuit diagram are all identical. Voltmeter $V_2$ shows a reading of $1.5\,\text{V}$. Ammeter $A_2$ has a reading of $0.50\,\text{A}$. Ammeter $A_3$ has a reading of $0.25\,\text{A}$. What are the readings shown by ammeter $A_1$ and voltmeter $V_1$?

Feb/March 2025

A student assembled the electrical circuit shown in Fig. 9.1.

Feb/March 2025

Fig. 3.1 depicts a mains electric heater that is used to heat a small room, and the diagram labels a shiny metal surface together with heating elements.

Feb/March 2025

A light-dependent resistor (LDR) has a low resistance when the light intensity is high and a high resistance in darkness.

Feb/March 2025

What is the purpose of a relay?

May/June 2016

The circuit diagram below includes three ammeters X, Y and Z. Which ammeter records the greatest reading?

May/June 2016

The diagram illustrates part of a circuit that is used to turn street lamps on and off automatically. In the evening, darkness falls. Which row shows what happens to the resistance of the light-dependent resistor (LDR) and to the potential difference (p.d.) across it?

May/June 2016

A domestic circuit contains a $30\ \text{A}$ fuse. Its purpose is to safeguard the wiring when the current in the circuit becomes too large. In which wire is the $30\ \text{A}$ fuse placed, and what happens when it works?

May/June 2016

Two meters are fitted into a circuit so that the current in a component and the potential difference across that component can be measured. Which meters are used, and how are they connected to the component?

May/June 2016

$P$ and $Q$ are the circuit symbols used for two electrical components. What components do $P$ and $Q$ stand for?

May/June 2016

The diagram illustrates two resistors linked in a circuit. What might be the total resistance of this resistor arrangement?

May/June 2016

The diagram illustrates part of a circuit that is used to turn street lamps on and off automatically. As evening falls, it becomes dark. Which row indicates what happens to the resistance of the light-dependent resistor (LDR) and to the potential difference (p.d.) across it?

May/June 2016

Why are the lamps in a household lighting circuit connected in parallel instead of in series?

May/June 2016

In the diagram, a cell is connected to two $6.0\,\Omega$ resistors. The currents $I_1$, $I_2$ and $I_3$ are marked. Which row gives the correct comparison of $I_2$ and $I_3$ with $I_1$?

May/June 2016

The diagram shows part of a circuit that is used to turn street lamps on and off automatically. In the evening, darkness falls. Which row shows how the resistance of the light-dependent resistor (LDR) changes and how the potential difference (p.d.) across the LDR changes?

May/June 2016

All four circuits illustrated contain an a.c. power supply, two diodes and a lamp. In which circuit does the lamp have a rectified current?

May/June 2016

The diagram illustrates a combination of logic gates. Input P is in logic state 0 (low), while input Q is in logic state 1 (high). What are the logic states at output X and at output Y?

May/June 2016

The diagram illustrates part of a circuit that is used to turn street lamps on and off automatically. As evening comes, it becomes dark. Which row indicates the change in the resistance of the light-dependent resistor (LDR) and the potential difference (p.d.) across it?

May/June 2016

A filament lamp has a small potential difference $V$ applied across it. The current $I$ through the lamp is then measured. $V$ is raised in steps and $I$ is recorded at each step. Which graph shows the results obtained?

May/June 2016

Each of the four circuits shown contains an a.c. power supply, two diodes and a lamp. In which circuit does the lamp carry a rectified current?

May/June 2016

P and Q are circuit symbols for two electrical components. Which components do P and Q represent?

May/June 2016

The diagram represents a set of combined logic gates. Input P is in logic state $0$ (low), while input Q is in logic state $1$ (high). What logic states appear at output X and at output Y?

May/June 2016

The diagram illustrates a section of a circuit that is used to switch street lamps on and off automatically. As evening falls, it becomes dark. Which row indicates how the resistance of the light-dependent resistor (LDR) changes and how the potential difference (p.d.) across it changes?

May/June 2016

All four circuits shown contain an a.c. power supply, two diodes and a lamp. In which circuit does the lamp carry a rectified current?

May/June 2016

A $3.0\,\Omega$ resistor is joined in parallel with a $6.0\,\Omega$ resistor. What is the combined resistance of the two resistors?

May/June 2016

The diagram illustrates a set of combined logic gates. Input P is in logic state 0 (low), while input Q is in logic state 1 (high). What logic states are produced at output X and at output Y?

May/June 2016

The diagram shows part of a circuit used to control street lamps automatically, switching them on and off. As evening falls, it becomes dark. Which row gives the effect on the resistance of the light-dependent resistor (LDR) and on the potential difference (p.d.) across it?

May/June 2016

A student sets up the circuit shown in Fig. 10.1 with a 12 V battery.

May/June 2016