# Chapter 23 Circuits.

## Presentation on theme: "Chapter 23 Circuits."— Presentation transcript:

Chapter 23 Circuits

23 Circuits Slide 23-2

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Drawing Circuit Diagrams
Slide 23-12

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? Answer: A Slide 23-13

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 Answer: A Slide 23-14

Kirchhoff’s Junction Law
Slide 23-15

Kirchhoff’s Loop Law Slide 23-16

Using Kirchhoff’s Laws
Slide 23-17

Checking Understanding
The diagram below shows a segment of a circuit. What is the current in the 200 resistor? 0.5 A 1.0 A 1.5 A 2.0 A There is not enough information to decide. Answer: B Slide 23-18

Answer The diagram below shows a segment of a circuit. What is the current in the 200 resistor? 0.5 A 1.0 A 1.5 A 2.0 A There is not enough information to decide. Answer: B Slide 23-19

Checking Understanding
The diagram below shows a circuit with two batteries and three resistors. What is the potential difference across the 200 resistor? 2.0 V 3.0 V 4.5 V 7.5 V There is not enough information to decide. Answer: A 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? 2.0 V 3.0 V 4.5 V 7.5 V There is not enough information to decide. Answer: A Slide 23-21

Series Resistors Slide 23-22

Parallel Resistors Slide 23-23

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? Slide 23-24

Example Problem What is the current supplied by the battery in the following circuit? Slide 23-25

Example Problem Find the current in and the potential difference across each of the resistors in the following circuit. Slide 23-26

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. Slide 23-27

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: 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. Which of the following circuits will provide more power? Slide 23-28

Analyzing Complex Circuits
Slide 23-29

Capacitor Combinations
Slide 23-30

Checking Understanding
Which of the following combinations of capacitors has the highest capacitance? Answer: B Slide 23-31

Answer Which of the following combinations of capacitors has the highest capacitance? B Answer: B Slide 23-32

Checking Understanding
Which of the following combinations of capacitors has the lowest capacitance? Answer: C Slide 23-33

Answer Which of the following combinations of capacitors has the lowest capacitance? C Answer: C Slide 23-34

RC Circuits Slide 23-35

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? Answer: C Slide 23-36

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 Answer: C Slide 23-37

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? Answer: B Slide 23-38

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 Answer: B Slide 23-39

Electricity in the Nervous System
The action potential Depolarization Repolarization Reestablishing resting potential Slide 23-40

Saltatory Conduction Slide 23-41

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. Slide 23-42

Summary Slide 23-43

Summary Slide 23-44

Additional Questions 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? 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. Answer: B Slide 23-45

Answer 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? 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. Answer: B Slide 23-46

Additional Questions 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? The brightness of the bulb is not affected. B. The bulb gets dimmer. C. The bulb gets brighter. The bulb initially brightens, then dims. E. The bulb initially dims, then brightens. Answer: B Slide 23-47

Answer 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? The brightness of the bulb is not affected. B. The bulb gets dimmer. C. The bulb gets brighter. The bulb initially brightens, then dims. E. The bulb initially dims, then brightens. Answer: B Slide 23-48

In the circuit shown below: 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. Answer: A&D (tie), B&C (tie) Slide 23-49