<p> Measuring Current in Electrical Circuits – A Lab Exercise Grade 9 Science Name: ______</p><p>Obtain the electrical circuit kits and 1 ammeter then follow these steps carefully while answering related questions (*) as you proceed.</p><p>Step 1 Notice that some ammeters have different ranges of measurement: Convert the following:</p><p>100 mA = A 0.05 A = mA</p><p>25 mA = A 0.300 A = mA</p><p>A: Series Circuits</p><p>Step 2 Connect a circuit as shown in the diagram. Use 2 cells, 1 lamp and 1 ammeter.</p><p>*Measure the amount of current at the positions shown. A1 =</p><p>A2 =</p><p>*How does the current compare between the above 2 positions? Can you suggest a reason for this result?</p><p>Step 3 Connect a circuit as shown in the diagram. Use 2 cells, 2 lamps in series and 1 ammeter. </p><p>*Measure the amount of current at the positions shown. A1 =</p><p>A2 =</p><p>A3 =</p><p>*How does the current compare at the above 3 positions? </p><p>*How do the current readings in step 3 compare to that in step 2? Suggest a reason for the difference. </p><p>*Suggest a rule or “law” regarding current in series circuits: B: Parallel Circuits</p><p>Step 4 Connect a circuit as shown in the diagram. Use 2 cells, 2 lamps in parallel and 1 ammeter.</p><p>*Measure the amount of current at the positions shown. A1 =</p><p>A2 =</p><p>A3 =</p><p>A4 = *How does A1 compare to A4? ______</p><p>*How does A2 compare to A3? ______</p><p>*How does A1 compare to A2 and A3? ______</p><p>*Suggest a rule or “law” regarding current in the above circuit:</p><p>Step 5 Connect a circuit as shown in the diagram. Use 2 cells, 3 lamps in parallel and 1 ammeter.</p><p>*Measure the amount of current at the positions shown. A1 =</p><p>A2 =</p><p>A3 =</p><p>A4 =</p><p>A5 = </p><p>*How does A1 compare to A5? ______</p><p>*How does A2, A3 and A4 compare to each other? ______</p><p>*How does A1 compare to A2, A3 and A4? ______</p><p>*Suggest a rule or “law” regarding current in parallel circuits:</p><p>The above “laws” are called “Kirchoff’s Current Laws”. Complete the following phrases:</p><p>When electric loads are connected in series, the current measurements ______.</p><p>When electric loads are connected in parallel, the current measurements ______.</p><p>When finished, carefully put the equipment back in the kit containers. Measuring Voltage in Electrical Circuits – A Lab Exercise</p><p>Grade 9 Science Name: ______</p><p>Obtain the electrical circuit kits and 1 voltmeter then follow these steps carefully while answering related questions (*) as you proceed.</p><p>A: Parallel Circuits</p><p>Step 1 Connect a circuit as shown in the diagram. Use 2 cells, 1 lamp and 1 voltmeter.</p><p>*Measure the voltage at the positions shown. V1 =</p><p>V2 =</p><p>*How does the voltage compare between the above 2 positions? Can you suggest a reason for this result?</p><p>Step 2 Connect a circuit as shown in the diagram. Use 2 cells, 2 lamps in parallel and 1 voltmeter.</p><p>*Measure the voltage at the positions shown. V1 =</p><p>V2 =</p><p>V3 = </p><p>*How does the voltage compare at the above 3 positions? </p><p>*How do the voltage readings at the lamps in step 2 compare to that in step 1? </p><p>*Suggest a rule or “law” regarding voltage in parallel circuits: B: Series Circuits</p><p>Step 3 Connect a circuit as shown in the diagram. Use 2 cells, 2 lamps in series and 1 voltmeter. </p><p>*Measure the voltage at the positions shown. V1 =</p><p>V2 =</p><p>V3 =</p><p>*How does V2 compare to V3? </p><p>*How does V1 compare to V2 and V3? </p><p>*Suggest a rule or “law” regarding voltage in the above circuit:</p><p>Step 4 Connect a circuit as shown in the diagram. Use 2 cells, 3 lamps in series and 1 voltmeter.</p><p>*Measure the voltage at the positions shown. V1 =</p><p>V2 =</p><p>V3 =</p><p>V4 =</p><p>*How does V2 compare to V3 and V4? ______</p><p>*How does V1 compare to V2, V3, and V4? </p><p>______</p><p>*Suggest a rule or “law” regarding voltage in the above circuit:</p><p>The above “laws” are called “Kirchoff’s Voltage Laws”. Complete the following phrases:</p><p>When electric loads are connected in series, the voltage measurements ______.</p><p>When electric loads are connected in parallel, the voltage measurements ______.</p><p>When finished, carefully put the equipment back in the kit containers.</p>