The method and the results are on the current and voltage lab. Do the analysis yourself first, then check the answers below.
Quick answer: An ammeter measures electric current in amperes and is connected in series, in the loop. These answers go with the grade 7 science lab on current and voltage: the graph, the calculations, the uncertainties and the conclusion explained, for all 8 analysis questions.
Model answers based on the sample data. Your own readings will differ a little because bulbs, cells and meters vary, but your totals should agree with the rules to within about 0.02 A and 0.1 V. Use the model working to check your method.
The readings are 0.19 A, 0.19 A and 0.18 A. The 0.01 A difference is within the reading uncertainty of the meters, so the current is the same everywhere in the loop.
Question 2 Series voltage
1.5 V + 1.4 V = 2.9 V. This equals the voltage across the cells, so the supply voltage is shared between the bulbs.
Question 3 Parallel current
0.32 A + 0.31 A = 0.63 A. This equals the main current, so the branch currents add up to the main current.
Question 4 Parallel voltage
Both bulbs have 2.9 V, the same as the cells. Each bulb is connected straight across the cells, so each has the full supply voltage.
A third bulb would draw about another 0.32 A, so the main current would be about 0.63 A + 0.32 A = 0.95 A.
Question 7 Meter placement
All of the current being measured must pass through the ammeter, so it must be in the loop. An ammeter across a bulb gives the current an almost resistance-free path, so the bulb goes out and the ammeter or cells could be damaged. Series only.
Question 8 Evaluation
The meters have a small reading uncertainty (±0.01 A), and the bulbs may warm up and change the current slightly during the measurement. Improve by repeating the readings, using the same meter in each position, and taking a mean. Repeat and use one meter.
