Yr 8 – Measuring Voltages

Construct the circuit shown, and answer each of the questions below.

Circuit 1 – 3 cells, 1 bulb, all in series

Q1. Measure the voltage (‘push’) from eachcell. Record your results below.

Voltage from Cell 1 / Voltage from Cell 2 / Voltage from Cell 3

Q2. Use a calculator to predicthow much voltage the cells will have altogether.

I predict the total voltage of the cells will be ______Volts

Q3. Measure the voltage across all the cellstogether– were you correct?

I measured the total voltage across the cells and it was ______Volts

Q4. Complete the sentence below:

Each cell had a voltage of approximately ______Volts, which added to give a total voltage of ______Volts.

Q5.Measure the voltage across the bulb to find out how much of the voltage from the cells is used up here.

……………………………………………………………………………………......

Q6. You should find that not all of the voltage from the cell is used pushing the charges through the bulb. Where do you think this voltage was used? (you may want discuss this in your group if you are not sure).

…………………………………………………………………………………………………………………

…………………………………………………………………………………………………………………

Circuit 2 – 3 cells, 2 bulbs, all in series

Q1. Measure the Voltage from eachcell, and then across all the cells together. Record your results below.

Voltage from
Cell 1 / Voltage from
Cell 2 / Voltage from
Cell 3 / Total Voltage

Q2. How much voltage is used up pushing the charges through eachbulb? Measure the voltages across

each bulb and record your results below.

Voltage across Bulb 1 / Voltage across Bulb 2 / Total

Q3. The cells are pushing the charges around the circuit, through the wires and bulbs. Do you think anything would change if we added another cell into the circuit? Explain your answer!

…………………………………………………………………………………………………………………..

…………………………………………………………………………………………………………………..

Circuit 3 – 3 cells, 3bulbs, all in series

Q1. Measure the total voltage across all the cells.

Total Voltage

Q2. Measure the total voltage across all the bulbs.

Voltage across both bulbs together