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SMC|Academic Programs|Physical Sciences|Parallel and series circuits

Parallel and series circuits

Series Circuits

Draw below a circuit with two round bulbs in series with two batteries

 

 

 

 

 

 

What happens when one of the bulbs is unscrewed? Why?

 

 

 

Redraw the circuit below. Measure and record the currents at different places around the circuit when both bulbs are in place. Explain your results.

 

 

 

 

 

 

Now, record and compare the current in a one bulb circuit with the two bulb circuit. (You will need to make a one bulb circuit!)

  one bulb series two bulb series
current/deflection    

Place a round bulb and a long bulb in series. What do you observe?

 

 

 

 

 

Parallel Circuits

Connect two LONG bulbs in PARALLEL. Draw the circuit below.

 

 

 

 

 

 

 

Unscrew one of the bulbs. What happens?

 

 

 

 

Redraw the parallel circuit below, and beneath it draw a series circuit with one long bulb. Measure and record the currents at different places around the circuits. Compare your results.

Parallel:

 

 

 

 

 

Series:

 

 

 

Unscrew one bulb from the parallel circuit and re-measure the currents around that circuit, and record them below on another drawing of the parallel circuit.

 

 

 

 

 

Try and get more than two long bulbs in parallel. Measure the currents in the loops and coming from the batteries. Comment on your findings.

 

 

 

 

Place a long and a round bulb in parallel. Record the currents/deflections carefully, and show below. Are they consistent with conservation of current?