Download Lab Summaries - Aurora City Schools

Ch 16: Electricity Lab Summaries
The purpose of this is to revisit the activities and apply what you learned. It is
not just copying answers form the labs. :-)
Static Electricity Exploration
negatively_
When you pulled the tape off the desk, the sticky side became _
charged because…
It pulled electrons off the desk surface
repelled_ because…
They are both positively charged (stick side
is negative) and like charges repel
When you put two nonsticky sides together, they _
When you put a sticky side and a nonsticky side together, they _
were
attracted_ because…
They are oppositely charged and opposite
charges attract
repelled_ because…
They are both negatively charged and like
charges repel
When you put two sticky sides together, they _
When you rub a balloon against your hair, it becomes _
because…
negatively_ charged
It pulls electrons off your hair
The balloon sticks to the wall because….
The negatively charged balloon pushes
electrons away from the wall leaving an induced
positive charge, which attracts the negative
balloon
The balloon attracts water because….
The negatively charged balloon pushes
electrons away from the water leaving an
induced positive charge, which is attracted to
the negative balloon
Where (specifically) in the lab do you see charging by:
Friction. Explain.
Rubbing balloon against hair
Induction. Explain.
Water being attracted by balloon
Really you don’t! If you left the
balloon on the wall long enough, the
charges would equalize through contact,
though
Contact. Explain.
pHETs: Electricity
After charging the balloon on the sweater:
What happens to the negative charges on the wall?
Explain why.
Push away, repelled
by negative balloon
What happens to the positive charges on the wall?
Explain why.
Nothing! They’re on the inside
(nucleus) of the atom. Electrons are
moving around outside the nucleus
When you rubbed both balloons on the sweater, what happened and why.
They stayed away from each other
because they were both negatively charged
When you rubbed only 1 balloon on the sweater what happened and why?
They moved towards each other
because one was negatively charged and
induced a positive charge in the other
What is the minimum number of things you need to make
a complete circuit? Name/show them.
3…a power source
(battery), a resistor (light
bulb) and a wire.
Show a circuit with 1 battery and two light bulbs
connected in series and in parallel.
Series:
Parallel:
If I add another light to the series circuit what will happen/why?
The lights will dim because the voltage is
spread over 3 resistors instead of 2.
If I add another light to the parallel circuit what will happen/why?
Nothing! Each resistor is its own circuit (loop)
of 1 battery and 1 bulb.
Does a switch always have to turn off all the lights in a circuit? Explain/show a
diagram.
No…depends where you put it…
Both of these switches turn off both lights
But these switches only turn off 1 light each
Do lights always have to be of the same brightness? Explain/show a diagram.
Depends on how many batteries are
connected and whether the resistors are in
series or parallel. In the diagram below, B & C
are half as bright at D because they are
connected in series.
Circuit Lab
As this is pictured, how many lights will light up?
All three
If I add another battery, what will happen to the lights?
All three would get brighter
Are these lights series or parallel? Explain.
Both…the ones on the left are parallel to each other, but in
series to the one at the bottom
If I put a switch at “x”, what will happen to the lights?
Only the light on the far left will go off
x
As this is pictured, how many lights will light up?
All three
If one of the lights burns out, what happens to the other
two? Explain.
They will all go out…it is one circuit
x
If I add another light at “x”, what happens to the lights?
Explain.
Only the one by x will dim. The others have their own
circuits.
Does the switch control all 3 lights? Explain.
No…just the top light
Are these lights series or parallel? Explain.
Parallel…not one right after the other; each has its
own circuit
Draw (a) switch(es) so that each light can be
controlled on its own.
Put the switch on each individual wire by the light
Add another light that is not affected by the switch.
When I add this, what happened to the brightness of
the bulbs?
They are unaffected…2 separate circuits
Add another light that is affected by the switch.
When I add this, what happened to the brightness of
the bulbs?
They are half as bright…same circuit