Standard circuit diagram symbols

A student connects a resistor across the terminals of a 9 V battery.

There is a current of 6 mA in the resistor.

Calculate the resistance of the resistor.

Describe how an additional component could be used to vary the current in the resistor.

A voltmeter has four different scales.

Which one of these scales would be most suitable to measure a voltage of 0.85 V?

*(c) The table in Figure 23 gives some information about series and parallel circuits.

Describe how a student can use ammeters and voltmeters to investigate the information given in Figure 23.

Your answer should include

• circuit diagrams showing how the currents and voltages can be measured

• a comparison of the results that would be expected

Space for circuit diagrams

Answer lines for this question are on page 37.

Figure 1 shows a circuit containing a battery and four other components.

Label the four components in Figure 1, using words from the box.

The circuit in Figure 1 is switched on.

A charge of 1.2 C leaves the battery in a time of 4.0 s.

Calculate the current in the circuit.

Use the equation

current =_........

A student investigates how current varies with potential difference across a filament lamp.

The student uses a power supply, a variable resistor, the filament lamp and two meters.

Part of the circuit diagram is shown in Figure 19.

Complete the circuit diagram needed for this investigation.

Figure 19

Another student repeats the investigation in part (a) using a data logger.

The data logger records observations using sensors instead of meters. The sensors are connected to a computer to collect and display the observations.

The data logger collects 555 pairs of data in 2 minutes.

The results are shown in Figure 20.

Suggest one advantage of using a data logger instead of meters in this investigation.

Describe how current varies with potential difference in the graph in Figure 20.

Use data from the graph in Figure 20 to show how the resistance changes with potential difference for the filament lamp.

Which of these equations is correct?

The unit of work is the joule.

Starting with the meaning of work, we may obtain an equivalent unit of work as Nm.

Using work F d

unit of work unit of force unit of distance Nm

The unit of potential difference is the volt.

Explain how, starting with the meaning of potential difference, we may obtain an equivalent unit of potential difference.

Figure 3 shows the parts in an electrical circuit.

Draw the circuit diagram of this electrical circuit in the space provided.

The battery symbol and some of the connecting wires have been drawn for you.

Figure 4 shows the current flowing into and out of point P in part of a circuit.

Which of these is the value of current I ?

There is a current of 0.46 A in a lamp.

Calculate the total charge that flows through the lamp in 30 seconds.

Use the equation

charge = currenttime in seconds

The voltage across the lamp is 6.0 V.

The current in the lamp is 0.46 A.

Calculate the energy transferred to the lamp in one minute.

Use the equation

energy transferred = currentvoltagetime in seconds

energy transferred =_........

This question is about electrical circuits.

Draw one straight line from each circuit symbol to its description.

Figure 1 shows a lamp in a circuit.

The lamp is switched on.

The current in the lamp is a flow of

The current in the lamp is 0.21 A.

Calculate the charge that flows through the lamp in a time of 300 s.

State the unit of charge.

Use the equation

charge = current × time

Figure 19 shows a lamp connected to a d.c. power supply.

The power supply provides a potential difference (voltage) of 4.5 V.

The current in the lamp is 0.30 A.

Calculate the resistance of the lamp.

Use the equation

Calculate the power supplied to the lamp.

Another identical lamp is added to the circuit, as shown in Figure 20.

The power supply provides the same potential difference as it provided in the circuit in Figure 19.

State and explain the difference between the brightness of the lamp in Figure 19 and the brightness of a lamp in Figure 20.

A student is given a low voltage power supply and 1 m of resistance wire.

The student uses these and other pieces of equipment to measure the resistance of just 50 cm of the resistance wire.

Draw a diagram of the circuit that the student should use.

Your circuit diagram should identify the pieces of equipment that the student uses.

Describe the difference between direct current (d.c.) and alternating current (a.c.) in electrical circuits.

Figure 3 shows a lamp connected to a d.c. power supply.

The power supply provides a potential difference (voltage) of 4.5 V.

The current in the lamp is 0.30 A.

Calculate the resistance of the lamp.

Use the equation

Calculate the power supplied to the lamp.

Another identical lamp is added to the circuit, as shown in Figure 4.

The power supply provides the same potential difference as it provided in the circuit in Figure 3.

State and explain the difference between the brightness of the lamp in Figure 3 and the brightness of a lamp in Figure 4.

A student is given a low voltage power supply and 1 m of resistance wire.

The student uses these and other pieces of equipment to measure the resistance of just 50 cm of the resistance wire.

Draw a diagram of the circuit that the student should use.

Your circuit diagram should identify the pieces of equipment that the student uses.

Which of these shows the correct circuit symbol for a thermistor?

A student investigates how the resistance of a thermistor varies with temperature.

Figure 16 shows a graph of the results of this investigation.

Describe how the resistance of this thermistor varies with temperature.

Draw the tangent to the curve at a temperature of 30 °C, to find the rate of change of resistance with temperature at 30 °C.

State the unit.

rate of change of resistance with temperature at 30 °C =_........ unit_........

Figure 17 shows the apparatus used for this investigation.

Explain one improvement in measurement that the student could make in the investigation.

In this investigation, the resistance can be measured in two ways.

Method 1 – use an ohmmeter.

Method 2 – use an ammeter and a voltmeter.

Method 1 Method 2

using an ohmmeter using an ammeter and voltmeter

Figure 18

Explain why method 2 gives more precise results than method 1.

Figure 1 shows an electrical circuit.

Draw a circuit diagram of the electrical circuit in Figure 1 in the space below.

When the current in a lamp is 0.15 A, the resistance of the lamp is 40 Ω.

Calculate the voltage across the lamp.

Use the equation

V = I × R

Figure 2 shows an ammeter that can read up to 5 A.

State the value of the current shown on the ammeter in Figure 2.

Which of these symbols is used to represent a thermistor in an electrical circuit?

A student investigates how the current in a lamp changes with the potential difference across the lamp.

The student uses the results to calculate the resistance of the lamp.

The results are shown in the table in Figure 17.

One value of resistance is missing from the table in Figure 17.

Calculate the value of resistance that is missing from the table.

missing resistance =_........ Ω

The student writes this conclusion:

‘The resistance of the lamp is directly proportional to the potential difference.’

Comment on the student’s conclusion. Use information from Figure 17 in your answer.

*(c) Figure 18 shows a battery connected to a filament lamp.

Explain, in terms of the movement of charged particles, how energy is transferred from the battery, through the lamp, to the surroundings.

Which of these symbols is used to represent a thermistor in an electrical circuit?

A student investigates how the current in a lamp changes with the potential difference across the lamp.

The student uses the results to calculate the resistance of the lamp.

The results are shown in the table in Figure 5.

One value of resistance is missing from the table in Figure 5.

Calculate the value of resistance that is missing from the table.

missing resistance =_........ Ω

The student writes this conclusion:

‘The resistance of the lamp is directly proportional to the potential difference.’

Comment on the student’s conclusion. Use information from Figure 5 in your answer.

The student used a power supply that had fixed output voltage settings. Each of these outputs was a whole number of volts.

Describe how the student could add a component to the circuit that would provide a continuously variable voltage across the lamp.