Quick answer: An ammeter measures electric current in amperes and is connected in series, in the loop. This grade 7 science test on current and voltage has 8 questions worth 20 marks, to do in 45 minutes: using meters, converting and a series circuit. The mark scheme is on a separate page; free printable PDF.
This test checks how to use ammeters and voltmeters and how to apply the rules for current and voltage in series and parallel circuits. You also have 45 minutes and 20 marks. Finally, write units with every answer and give reasons where the question says explain.
Level: Grade 7 science (Year 8 · Class 7) · Curriculum: MS-PS2-3
Question 1 Using meters (3 marks)
- Firstly, state what an ammeter measures and its unit. (1 mark)
- Then describe how an ammeter is connected. (1 mark)
- Finally, describe how a voltmeter is connected. (1 mark)
Question 2 Converting (2 marks)
- Firstly, convert 480 mA into amperes. (1 mark)
- Then convert 1.25 A into milliamperes. (1 mark)
Question 3 A series circuit (3 marks)
Firstly, look at the series circuit in the figure.
- Firstly, calculate the voltage across bulb 2. (1 mark)
- Then state the reading of an ammeter placed after bulb 2. (1 mark)
- Finally, explain your answer to part b. (1 mark)
Question 4 A parallel circuit (3 marks)
In a parallel circuit, the main ammeter reads 1.00 A and the ammeter in branch 1 reads 0.65 A. Also, the supply is 6.0 V.
- Firstly, calculate the current in branch 2. (1 mark)
- Then state the voltage across branch 2. (1 mark)
- Finally, state the main current if branch 2 is disconnected. (1 mark)
Question 5 Ammeter across a lamp (2 marks)
Afterwards, Nia in Cape Town connects an ammeter across a lamp. Then predict what happens to the lamp and explain why. (2 marks)
Question 6 Current in a series loop (2 marks)
A student says that the current gets smaller after each bulb in a series circuit because the bulbs use it up. Therefore explain why the student is wrong. (2 marks)
Question 7 Overloading a socket (3 marks)
You plug three appliances in parallel into one extension lead. So they draw 0.30 A, 0.45 A and 0.60 A. Also, the lead has a 1.0 A fuse.
- Firstly, calculate the total current. (1 mark)
- Then explain whether the fuse will blow. (1 mark)
- Finally, state which single appliance could be removed so that the fuse does not blow. (1 mark)
Question 8 Water analogy (2 marks)
For example, use the idea of water in pipes to explain the difference between current and voltage. (2 marks)
