IGCSE Physics – Electricity Practice Test

These questions are part of the practice quiz. Start practicing

• Which statement correctly describes the direction of conventional current with respect to terminals?
• In a series circuit of resistors 4 Ω and 6 Ω connected to a 24 V source, what is the current?
• Two resistors of 10 Ω and 20 Ω are connected in parallel to a 12 V supply. What is the total current drawn from the source?
• What is the purpose of the outer insulation in a plug?
• Which device converts AC to DC in power supplies?
• A lamp marked 40 W at 230 V is connected. What is its resistance?
• A 9 V supply is connected to a resistor. If the resistance increases from 2 Ω to 3 Ω, what happens to the current?
• A fuse in a circuit is rated 3 A. If 4 A flows, what happens to the fuse and why?
• A voltmeter is used to measure voltage in a circuit by connecting in parallel to a component.
• If a wire has resistivity ρ, length L, and cross-sectional area A, giving R = ρL/A, what happens to R if the length is doubled while the material and area remain the same?
• What happens when two objects have like charges?
• What is a battery?
• What is the source of energy in a circuit?
• What is the current formula?
• A resistor is connected to a 12 V supply and draws 3 A. What is its resistance?
• If 5 coulombs of charge pass and the voltage is 2 volts, what is the energy transferred?
• A battery has an internal resistance of 0.2 Ω. If the external circuit is 10 Ω and the battery supplies 9 V open-circuit, what is the current when connected?
• Ohm's Law states the current that flows through a component is directly proportional to the voltage across the component.
• In a series circuit, how are voltages across components related to their resistances?
• If an electric heater uses 3 kW when on, how much energy does it use in 4 hours?
• As voltage increases on a filament and the filament heats, what happens to the current and resistance?
• What is the unit of voltage and what does one volt represent?
• What is the process called when a charged object causes a neutral object to rearrange its charges without contact?
• Which statement about the earth pin is correct?
• How is energy transferred in a circuit calculated?
• In a parallel circuit, what happens to voltage and current?
• If a battery with internal resistance r is connected to an external circuit with resistance R_ext, the current is I = E/(R_ext + r). When R_ext is much larger than r, the current is approximately
• A series circuit is defined as?
• Which term describes devices that obey Ohm's Law?
• What is the voltage formula that relates voltage to current and resistance?
• The coulomb is the SI unit of which quantity?
• Which circuit type has current that can split and flow along different branches?
• If the voltage across a fixed resistance is doubled, what happens to the current?
• What is electricity commonly defined as?
• What is the total resistance in a series circuit containing resistors 2 Ω, 3 Ω, and 5 Ω?
• Residual current devices (RCDs) are:
• What describes a negatively charged object?
• Why does the resistance of a metal conductor increase with temperature?
• In a parallel arrangement of a 6 Ω resistor across a 12 V supply, what is the current through the 6 Ω resistor?
• Which statement best describes the neutral wire?
• A 1000 W kettle runs for 0.5 hours. How much energy does it use in kWh?
• What device is used to measure current?
• If 60 joules of work are done in 3 seconds, what is the power?
• Which term defines the resistance that occurs when one surface moves over another?
• If a resistor has a fixed voltage across it and its current is doubled, what happens to power?
• What is the purpose of a cable grip?
• How are semiconductors formed?
• A mains cable consists of which?
• What does the outer insulation provide?
• Which device primarily uses direct current?
• What are the standard units for resistance and electric current?
• Which statement describes a conductor?
• What is the purpose of the fuse in a plug?
• What is an insulator?
• In a parallel circuit with two identical resistors, what is the relationship between total current and the current through one resistor?
• Which component emits light when heated?
• What does double insulation mean?
• When a filament bulb is dim, the filament is cold and has
• A battery is defined as what in terms of cells and energy conversion?
• In a circuit with a fixed voltage, if the resistance doubles, what happens to current and power?
• Which statement about the live wire is true?
• What is the SI unit of charge?
• Which of the following is an insulator?
• What is the function of the cable grip in a plug?
• What happens when an object gains electrons?
• How does increasing the cross-sectional area affect resistance?
• What is the difference between energy transfer and power in circuits?
• LED stands for which of the following?
• Which of the following is NOT an example of an insulator?
• Which statement about a filament bulb's I–V behavior is true?
• The energy transferred in an electric circuit is given by which expression?
• Why are house circuits often wired in parallel rather than in series?
• What is a thermistor and how does its resistance change with temperature?
• A short circuit is characterized by what resistance in the branch?
• In a circuit containing a 10 Ω resistor in parallel with a 10 Ω resistor, what is the current ratio if the same voltage is across both?
• An ammeter for current in a circuit should be placed where?
• Which statement best defines electricity?
• What term describes the difference in electrical potential energy between two points?
• Which statement correctly describes the live wire?
• Why is a voltmeter connected in parallel to measure the voltage across a component?
• Which description best defines earthing?
• What is the term for a device that does not obey Ohm's Law?
• A parallel circuit is defined as?
• In a series circuit, what happens to voltage and current?
• Which device is an electric lamp consisting of a wire filament that emits light when heated and is non-ohmic?
• What color identifies the earth wire in a mains cable?
• Which statement is true about alternating current?
• If the length of a conductor is halved, what happens to its resistance?
• In the domestic supply, what is the typical mains voltage and frequency in the UK?
• What is the relationship between electron flow and conventional current?
• A resistor is a device used to introduce some amount of resistance into a circuit.
• Which statement correctly defines current?
• Which term describes the accumulation of excess electric charge on an object?
• How does increasing resistance affect the current in a circuit?
• Charge is defined as what?
• What happens when an object loses electrons?
• In a parallel circuit with a 30 Ω and 60 Ω resistor connected to a 15 V supply, what is the total current drawn from the source?
• Why is a circuit breaker used instead of a fuse in some circuits?
• In a parallel circuit with several branches, how is the total current drawn from the power source related to the branch currents?
• Two identical resistors, each R, connected in parallel. Compared with a single resistor of resistance R, the total resistance is what?
• Which of the following are examples of conductors?
• Double insulation is designed to prevent electric shocks by ensuring what condition?
• A fuse is best described as what?
• Three resistors—2 Ω, 6 Ω, and 3 Ω—are connected in parallel across a 12 V source. Which set of branch currents and total current is correct?
• Why is energy used by household appliances billed in kilowatt-hours rather than joules?
• What term describes devices whose resistance does not remain constant under changing conditions?
• A short circuit is best described as?
• What is the function of a mains cable?
• What is the purpose of an earth wire?
• According to the energy transfer formula E = I V t, which factors affect the energy transferred?
• Why does the resistance of a metal depend on its temperature?
• How does a fuse protect a circuit?
• Voltage is defined as which of the following?
• An 8 Ω resistor carries 1.5 A. Which option gives the correct voltage across it and the power dissipated?
• Power is defined as
• A 60 W bulb is connected to a 230 V supply. What is the current through the bulb?
• In an electrical circuit, resistance is the component's opposition to the electric flow.
• A house uses a 5 kW heater for 2 hours. How much energy is consumed, in kWh?
• Which device trips when there is leakage current to protect a person from electric shock?
• What happens to the resistance of a filament as its temperature increases?
• Conventional current direction is described as flowing from the positive side of the battery to the negative side. Which option best matches this description?
• What is the purpose of an RCD in a household circuit?
• Which formula represents power?
• What uses alternating current?
• What is the SI unit for current?
• In the typical wiring described, the earth wire is at what potential?
• Uses of diodes include:
• If the voltage across a resistor doubles while its resistance remains the same, what happens to the current?
• In a parallel circuit, if one branch has infinite resistance (an open circuit), what happens to the equivalent resistance of the network?
• In a parallel circuit, current is:
• If a device operates for 3 hours at a power of 1.5 kW, how much energy is used in kilowatt-hours?
• How does the resistance of a cable affect the current drawn by a device?
• Which component allows current to flow in only one direction?
• A 5-ohm resistor carries a current of 2 A. What is the potential difference across it?
• What is the value of 1 kilowatt-hour in joules?
• In a circuit with a fixed voltage, what is the effect of increasing a resistor's resistance on the current?
• The resistance of a metal increases with temperature.
• What hazard can result from overloading a circuit or using damaged insulation?
• A 9 V battery drives a circuit with resistance of 2 Ω. What is the power delivered by the battery?
• Which term describes a resistor whose resistance can be changed by adjusting the portion of the resistor the current travels through?
• In a resistor, the resistance stays the same.
• If a 2 kW device runs for 1.5 hours, what is the energy in kWh?
• What is current in an electric circuit?
• A semiconductor whose resistance decreases rapidly with increasing temperature is called what?
• What is static electricity?
• What is the unit of resistance?
• What is current?
• Which statement describes a diode's current–voltage behavior?
• Why are metals good electrical conductors?
• In a resistor's current–voltage graph, which statement is correct?
• Which term refers to a property of matter that can be positive, negative, or neutral?
• What is the function of a two-way switch in a circuit?
• Conventional current flows from which terminal to which in a circuit diagram?
• In a series circuit, does the same current flow through all components?
• If two resistors in parallel have equal resistance, how does the total resistance compare to each individual resistor?
• A detector whose resistance decreases as light intensity increases is known as what?
• What is the unit used to measure electrical power?
• Mains electricity refers to which description?
• What happens when a fuse carries more current than its rating?
• If the resistivity ρ of a conductor doubles while length and cross-sectional area remain the same, what happens to the resistance?
• The wire that connects the metal case of an appliance to earth is called the:
• Which term best describes a device that obeys Ohm's Law?
• Two resistors, 6 Ω and 3 Ω, connected in parallel to a 12 V supply. What is the total current drawn from the supply?
• Power in a branch with I = 6 A and R = 2 Ω is
• Which materials are examples of insulators?
• The unit Ohm is denoted by which symbol?
• Direct current (DC) is defined as:
• Diodes are described as valves for current.
• Which expression gives the current through a resistor given voltage V across it and resistance R?
• What is the Van de Graaff generator?
• What is the energy transfer formula for a resistor?
• In a typical three-pin plug, what are the voltages for live, neutral, and earth wires?
• What are sparks?
• What happens when two objects have opposite charges?
• Which color is typically used for the neutral wire in a mains cable?
• A 4 Ω resistor and a 12 Ω resistor are connected in parallel to a 24 V supply. Find the total resistance.
• Which of the following is an example of an Ohmic conductor?
• Which formula gives resistance?
• In a series circuit, current is:
• Which device is a semiconductor that allows current to flow in only one direction?
• In a parallel circuit, what is the voltage across each resistor relative to the source voltage?
• A 15 V source powers two resistors in parallel: 30 Ω and 60 Ω. What is the total resistance?
• Power is defined as what?
• A variable resistor is defined as?
• A lamp is connected to a 240 V supply and has a power rating of 120 W. What is the current through the lamp?
• A circuit contains a 20 Ω resistor in series with a 5 Ω resistor connected to a 75 V supply. What is the current in the circuit?
• What unit is commonly used for electrical energy in domestic calculations and energy bills?
• Which statement describes why metals conduct electricity well?
• What does current represent in an electrical circuit?
• What does the earth wire do?
• Which device's resistance changes with light intensity?
• In a series circuit carrying 2 A, what is the voltage across a 3 Ω resistor?
• Which formula correctly gives the total resistance of two resistors in parallel?
• Why do charged objects attract neutral objects?
• A circuit breaker is:
• What is the relationship between voltage, current, and resistance in a practical circuit with a fixed supply?
• Which device's resistance decreases as temperature increases?
• Alternating current (AC) is defined as:
• What describes a positively charged object?
• A thermistor used as a temperature sensor is NTC. If the temperature rises, what happens to the resistance and current for a fixed supply voltage?
• Which of the following is a use of static electricity?
• In a parallel circuit, what is the main property of current in parallel branches?
• Which equation correctly expresses power using voltage and resistance only?
• If you have a 48 Ω resistor in parallel with a 16 Ω resistor across a 12 V supply, what is the current through each resistor and the total current?
• Which of the following lists two common safety features of domestic electrical systems?
• In parallel circuits, the equivalent resistance is
• The current through a component is directly proportional to the voltage across it. Which statement describes this aspect of Ohm's Law?
• If you double the number of identical resistors in parallel, what happens to the total resistance?
• Which of the following uses direct current?
• One watt is equal to?