Action and use of circuit components

The diagram shows a circuit. In which position should an ammeter be connected to measure the lowest current?

May/June 2015

A student is carrying out an investigation into resistance with the circuit diagram shown. The resistance of $R$ is about $5\,\Omega$. Which ranges are the most suitable for the voltmeter and the ammeter?

May/June 2016

Which component, when placed in a circuit, permits current to flow in only one direction?

May/June 2016

A potential divider is connected across the terminals of a $6.0\,\text{V}$ supply. When $R$ is set to $6.0\,\Omega$, the voltmeter readings $V_1$ and $V_2$ are the same. What changes in the readings if the resistance of $R$ is then increased?

May/June 2016

The readings from an ammeter and a voltmeter are used to determine the resistance of resistor $R$. In which circuit are the ammeter and voltmeter positioned correctly?

May/June 2017

The diagram illustrates an alarm system. What occurs when battery P is disconnected?

May/June 2018

In the circuit shown, the room temperature and the light intensity influence the current. Under which conditions is the current in the circuit greatest?

May/June 2018

In the circuit diagram, a variable resistor $R$ is connected in parallel with the lower section of a potential divider. The resistance of $R$ increases. What happens to the two voltmeter readings?

May/June 2018

A car battery allows current to flow in one direction only. To recharge the battery, current must flow in the opposite direction. Which circuit charges the battery, using an alternating current (a.c.) supply and a diode?

May/June 2019

The diagram illustrates a simple circuit. What occurs when the resistance of the variable resistor is increased?

May/June 2019

A car battery provides a current in one direction. If a current flows in the opposite direction, the battery is recharged. Which circuit uses an alternating current (a.c.) supply and a diode to recharge the battery?

May/June 2019

Fig. 8.1 presents a circuit diagram that includes a $2000\,\Omega$ resistor with constant resistance and a thermistor.

May/June 2019

A potential divider is made from a light-dependent resistor (LDR) and a resistor linked to a $6.0\,\text{V}$ battery. The output is $3.0\,\text{V}$. What resistance does the LDR have?

May/June 2023

A potential divider is formed using a light-dependent resistor (LDR) together with a $6.0\,\text{k}\Omega$ fixed resistor. This potential divider is placed in series with a 12 V d.c. power supply, and a voltmeter is placed across the $6.0\,\text{k}\Omega$ resistor. Fig. 8.1 shows the circuit diagram. Light falls on the LDR. The resistance of the LDR is $2.0\,\text{k}\Omega$.

Oct/Nov 2015

A light-emitting diode (LED) is linked to an alternating current (a.c.) supply. The LED switches on and off repeatedly. In which direction is the current in the LED when it is producing light?

Oct/Nov 2017

A circuit contains a thermistor and a light-dependent resistor (LDR). The resistance of the thermistor and the resistance of the LDR both rise. What alteration would produce this?

Oct/Nov 2017

An electric current flows through a resistor. Which energy transfer takes place?

Oct/Nov 2020

Which circuit is arranged to measure the current in the fixed resistor and the potential difference (p.d.) across that same resistor?

Oct/Nov 2021

The diagram depicts an LED in a circuit with a resistor and an a.c. power supply of frequency $2.0\,\text{Hz}$. Which statement is correct?

Oct/Nov 2021

A student sets up four circuits with two identical cells, two identical resistors and a motor. Which circuit makes the coil of the motor rotate most quickly?

Oct/Nov 2025

Which component in an electric circuit is used to detect temperature changes?

Oct/Nov 2025