Download Chapter 2 Review Answers 09-10 - Parkway C-2

Chapter 2 Review
Get out your notebooks
and open up to your
review.
You must have it COMPLETED to
stay and go over the answers!!!
Reviewing Key Terms
• 1. The attraction or repulsion between
electric charges is called__________.
– B. electric force (p. 36)
• 2. The potential difference that causes
charges to move in a circuit is
called____.
– D. voltage (p. 48)
Checking Concepts
• 6. Conduction is the process of charging
an object with out touching it.
– False: INDUCTION (p. 38-39)
• 7. Electrical resistance is low in a good
conductor.
– True (p. 47)
• 9. In a series circuit, all parts of the
circuit are connected in a single path.
– True (p. 64)
• 11. Describe the three ways in which an
object can become charged.
– p. 38
– An object can become charged by friction,
conduction, or by induction.
• Friction-Electrons are rubbed off one object
onto another object
• Conduction- One charged object touches
another and transfers charges
• Induction- an electric field around a charged
object attracts or repels electrons in another
object
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• 12. What units are used to measure voltage,
current, and resistance. (KIDS DIDN’T HAVE TO
DO, but they may want to write this down :) )
–
–
–
–
Voltage- volts
Current- ampere (amp)
Resistance- the ohm
p. 61
• 13. Explain how the components of an
electrochemical cell produce voltage.
– An electrochemical cell consists of two different metals
called electrodes immersed in an electrolyte. A voltage is
produced when one electrode reacts with the electrolyte
and becomes negatively charged and the other electrode
reacts with the electrolyte and becomes positively
charged.
– p. 56
• 14. What is Ohm’s Law?
– Resistance is equal to the voltage divided
by the current.
– p. 61
• 15. What would happen if the circuits in
your school building were series
circuits? Explain.
– If one electric appliance or device in the
building failed, all the others would stop
working, too. The single path for the
current in a series circuit would be broken.
– p. 64
Thinking Critically
• 18. Classifying: Identify each of the following
statements as characteristic of series circuits,
parallel circuits, or both:
– p. 64-65
– A. Current= Voltage divided by Resistance
• both
– B. Total resistance increases as more light
bulbs are added.
• series
– C. Total resistance decreases as
more branches are added.
• parallel
– D. Current in each part of the
circuit is the same.
• series
– E. A break in any part of the
circuit will cause current to stop.
• series
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• 19.Is the electroscope shown below
charged or uncharged? Explain.
– Charged: the evidence is that the leaves
are shown repelling each other, which
means that the charge of both leaves is the
same.
– p. 40, figure 5
• 22. A toaster is plugged into a 120-volt
socket. If it has a current of 0.25 amps
in its coils, what is the resistance of the
toaster? Show your work.
– R=V/I; R= (120 V)/ (0.25 A)= 480 Ω
– p. 61
• 24. Is the circuit in the illustration a
series or parallel circuit? Explain.
• 23. The voltage of a car battery is 12
volts. When the car is started, the
battery produces a 40-amp current.
How much power does it take to
start the car?
– P=V I; P= 12V x 40.0A= 480 W
– p. 69
– Both. Bulbs 2 and 3 are in parallel with each
other, and both are in series with bulb 1.
• 25. Would the other bulbs continue to
shine if you removed bulb 1?
– No, they would go out because the circuit
would be broken.
Would they shine if you removed bulb 2
instead? Explain your reasoning.
– Yes, they would be lit because the current has an
alternate route.
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From p. 56-57
• 26. Will any of the bulbs be light if
you open the switch? Explain.
– None of the bulbs would be lit if the
switch were open because it would break
the circuit and stop the current.
• What type of energy is transferred
from a battery to a wire? From a
wire to a bulb?
– From a battery to a wire, chemical
energy is changed into electrical energy.
– From a wire to a bulb, electrical energy
is changed into heat or light energy.
• As the energy sources (batteries)
are added to a circuit, what happens
to the voltage?
– It increases. The amount of voltage in a
circuit is equal to the sum of the voltage
of the batteries in the circuit.
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