10
7
8
9
SERiES CiRCUiTS
SERiES CiRCUiT wiTH TwO BULBS
This type of circuit is known as a “series” circuit. Turn on the switch
and observe. The two bulbs light up, but they are not very bright. The
filament is almost orange in colour. When assembled in series, the
bulbs have to share the energy from the battery. The disadvantage of a
series circuit is that if one bulb blows the others do not light up.
Now try this:
turn off the switch and unscrew one of the two bulbs.
Turn on the switch again. What happens? The second bulb does not
light up because you have opened the circuit and the current cannot
flow through.
SERiES CiRCUiT wiTH BULB AND mOTOR
Make the same circuit as in Activity 7 but use the motor instead
of one of the two bulbs. Observe how the power reduces as it is
shared between the motor and the bulb. The bulb lights up weakly
and the motor is not powerful enough to make the discs work.
SERiES CiRCUiT wiTH TwO
BULBS AND LESS pOwER
Make a series circuit with the two bulbs connected to only one
battery. Turn on the switch. Carefully observe the filament of the
bulb. The bulbs hardly light up and the filament only has little
colour. The power supplied by one battery is not enough to light
the two bulbs.
ELECTRO
LAB
