Transcript Slide 1
Chapter 23 Circuits
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PowerPoint ® Lectures for College Physics: A Strategic Approach, Second Edition
23
Circuits
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Drawing Circuit Diagrams
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Checking Understanding
The following circuit has a battery, two capacitors and a resistor. Which of the following circuit diagrams is the best representation of the above circuit?
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Answer
The following circuit has a battery, two capacitors and a resistor. Which of the following circuit diagrams is the best representation of the above circuit?
A
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Kirchhoff
’
s Junction Law
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Kirchhoff
’
s Loop Law
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Using Kirchhoff
’
s Laws
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Checking Understanding
The diagram below shows a segment of a circuit. What is the current in the 200 resistor?
A.
B.
C.
D.
E.
0.5 A 1.0 A 1.5 A 2.0 A There is not enough information to decide.
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Answer
The diagram below shows a segment of a circuit. What is the current in the 200 resistor?
A.
B.
C.
D.
E.
0.5 A
1.0 A
1.5 A 2.0 A There is not enough information to decide.
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Checking Understanding
The diagram below shows a circuit with two batteries and three resistors. What is the potential difference across the 200 resistor?
A.
B.
C.
D.
E.
2.0 V 3.0 V 4.5 V 7.5 V There is not enough information to decide.
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Slide 23-20
Answer
The diagram below shows a circuit with two batteries and three resistors. What is the potential difference across the 200 resistor?
A.
B.
C.
D.
E.
2.0 V
3.0 V 4.5 V 7.5 V There is not enough information to decide.
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Series Resistors
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Parallel Resistors
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Example Problems
There is a current of 1.0 A in the circuit below. What is the resistance of the unknown circuit element?
What is the current out of the battery?
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Example Problem
What is the current supplied by the battery in the following circuit?
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Example Problem
Find the current in and the potential difference across each of the resistors in the following circuit.
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Example Problems
What is the equivalent resistance of the following circuit?
Find the current in and the potential difference across each element in the following circuit.
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Example Problem
As we saw in the previous chapter, a resistor connected to a power supply works as a heater. Suppose an investigator is using a resistor (a length of nichrome wire in an insulating sheath) connected to a battery to warm a solution in the laboratory. It ’ s a simple circuit: A.
What power does the resistor provide to warm the solution?
The investigator then decides that this warming is happening too slowly. She has another resistor, but doesn ’ t have another battery. She needs to connect both resistors and the battery into a single circuit.
B.
Which of the following circuits will provide more power?
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Analyzing Complex Circuits
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Capacitor Combinations
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Checking Understanding
Which of the following combinations of capacitors has the highest capacitance?
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Answer
Which of the following combinations of capacitors has the highest capacitance?
B
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Checking Understanding
Which of the following combinations of capacitors has the lowest capacitance?
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Answer
Which of the following combinations of capacitors has the lowest capacitance?
C
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RC
Circuits
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Checking Understanding
The following circuits contain capacitors that are charged to 5.0 V. All of the switches are closed at the same time. After 1 second has passed, which capacitor is charged to the highest voltage? © 2010 Pearson Education, Inc.
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Answer
The following circuits contain capacitors that are charged to 5.0 V. All of the switches are closed at the same time. After 1 second has passed, which capacitor is charged to the highest voltage?
C
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Checking Understanding
The following circuits contain capacitors that are charged to 5.0 V. All of the switches are closed at the same time. After 1 second has passed, which capacitor is charged to the lowest voltage? © 2010 Pearson Education, Inc.
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Answer
The following circuits contain capacitors that are charged to 5.0 V. All of the switches are closed at the same time. After 1 second has passed, which capacitor is charged to the lowest voltage?
B
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Electricity in the Nervous System
The action potential Depolarization Repolarization Reestablishing resting potential © 2010 Pearson Education, Inc.
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Saltatory Conduction
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Example Problem
There are some diseases that result in a thinning of the myelin sheath that surrounds peripheral neurons —those that carry signals between the spinal cord and the limbs. How will this thinning affect nerve conduction speed? Explain this using the model for nerve conduction developed in the chapter.
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Summary
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Summary
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Additional Questions
1. In the circuit below, the switch is initially open and bulbs A and B are of equal brightness. When the switch is closed, what happens to the brightness of the two bulbs?
A.
B.
C.
D.
The brightness of the bulbs is not affected.
Bulb A becomes brighter, bulb B dimmer.
Bulb B becomes brighter, bulb A dimmer.
Both bulbs become brighter.
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Answer
1. In the circuit below, the switch is initially open and bulbs A and B are of equal brightness. When the switch is closed, what happens to the brightness of the two bulbs?
A.
B.
C.
D.
The brightness of the bulbs is not affected.
Bulb A becomes brighter, bulb B dimmer.
Bulb B becomes brighter, bulb A dimmer.
Both bulbs become brighter.
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Additional Questions
2. In the circuit shown below, the switch is initially closed and the bulb glows brightly. When the switch is opened, what happens to the brightness of the bulb? A.
B.
C.
D.
E.
The brightness of the bulb is not affected.
The bulb gets dimmer.
The bulb gets brighter.
The bulb initially brightens, then dims.
The bulb initially dims, then brightens.
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Answer
2. In the circuit shown below, the switch is initially closed and the bulb glows brightly. When the switch is opened, what happens to the brightness of the bulb? A.
B.
C.
D.
E.
The brightness of the bulb is not affected.
The bulb gets dimmer.
The bulb gets brighter.
The bulb initially brightens, then dims.
The bulb initially dims, then brightens.
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Additional Example Problems
1. In the circuit shown below: A.
B.
Rank in order, from most to least bright, the brightness of bulbs A –D. Explain.
Describe what, if anything, happens to the brightness of bulbs A, B, and D if bulb C is removed from its socket. Explain. © 2010 Pearson Education, Inc.
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Additional Example Problems
2. In the circuit shown below, rank in order, from most to least bright, the brightness of bulbs A –E. Explain. © 2010 Pearson Education, Inc.
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Additional Example Problems
3. In the circuit shown below: A.
How much power is dissipated by the 12 Ω resistor?
B.
What is the value of the potential at points a, b, c, and d?
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