ScienceFreePrintable

Current and Resistance Experiment

A free science worksheet ready for your classroom. Open in Kuraplan to grab the print-ready PDF, customize it for your students, or generate a fresh version in seconds.

Download now

Name:Date:

Current and Resistance Experiment

A science club is testing how a variable resistor changes current in a simple series circuit. Use the supplied results to analyse the pattern, then plan a fair test. Safety: use only a low-voltage battery pack, check the circuit before switching on, and disconnect the battery between readings. Never connect a circuit directly to mains electricity.

Circuit and results

In a series circuit, the same current flows through every component. The results below were collected with a 6.0 V battery pack. The variable resistor was adjusted while the other components stayed the same.

Resistance (Ω)

Current (A)

Brightness (1–5)

0.60

0.30

0.20

Read the evidence

Answer each question using the circuit information or results table. Include units where they are needed.

1.As resistance increased from 10 Ω to 30 Ω, what happened to the current? Choose the best answer.

It increased.
It decreased.
It stayed the same.

2.At which resistance setting was the current greatest? Give the current reading with its unit.

3.Using the results table, describe the relationship between resistance and lamp brightness.

4.The battery voltage stayed at 6.0 V. Use Ohm’s law, V = I × R, to check the 20 Ω result. Show the calculation and state whether it agrees with the table.

5.What is the main independent variable in this investigation?

6.Name one variable that should be kept the same to make this a fair test, and explain why.

7.True or false: In a series circuit, the ammeter is connected in parallel with the lamp.

TrueFalse

8.A group records 0.34 A at 20 Ω, while the other trials give 0.30 A. Suggest one sensible step the group could take before deciding whether this result is unusual.

9.Predict the current at 40 Ω if the voltage remains 6.0 V and the circuit follows Ohm’s law. Show your working.

10.Plan one improvement that would make the investigation’s results more reliable. Explain how it helps.

Sketch a labelled series circuit containing a battery pack, switch, ammeter, variable resistor and lamp. Show the ammeter in the correct position.