chapter26 - Electric circuit components Capacitor stores...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
Electric circuit components Capacitor – stores charge and potential energy, measured in Farads (F) Battery – generates a constant electrical potential difference ( V) across it. Measured in Volts (V). Resistor – resists flow of charge due to scattering; dissipates energy. Measured in Ohms ( ) Direct Current (DC) circuits First, we will consider circuits with batteries and resistors. R V=5V I
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Resistors in Series I I I I = = = 3 2 1 3 3 2 2 1 1 IR V V IR V V IR V V yb xy ax = = = = = = () 3 2 1 3 2 1 R R R I V V V V ab + + = + + = The current through all resistors is the same 3 2 1 R R R R IR V eq eq ab + + = = Resistors in Series = i i eq R R Adding resistors in series always increases the total resistance.
Background image of page 2
Resistors in Series: Example Calculate I and V across each resistor V R A R B I bat I A I B R A = 1.0 R B = 3.0 V = 6 Volts V R A R B I bat I A I B Two different wires are connected to a battery in series (in a chain, one after another). How does the current in upper wire A compare to the current in lower wire B? A) i A > i B B) i A < i B C) i A = i B D) Impossible to determine. Clicker Question
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
What is the equivalent resistance? = + = + = 0 . 4 0 . 3 0 . 1 2 1 R R R eq What is the current through the circuit? Assuming everything is Ohmic, V=IR A V R V i i i eq B A 5 . 1 0 . 4 6 = = = = = V R A R B I bat I A I B Resistors in Series: Example What about the Voltage change across each resistor? V R A R B I bat I A I B R A = 1.0 Ω, i A =1.5 A =1.5 A R B = 3.0 Ω, i B = 1.5 A V = 6 Volts V A R i V V A A A A 5 . 1 ) 0 . 1 )( 5 . 1 ( = = = = V A R i V V B B B B 5 . 4 ) 0 . 3 )( 5 . 1 ( = = = = Resistors in Series: Example
Background image of page 4
V R A R B I bat I A I B Clicker Question If we consider the Voltage change starting at Point P and going all the way around the circuit loop back to Point P, what is the total V? Α)∆ V = +6.0 Volts Β)∆ V = +1.5 Volts C) V = -4.5 Volts D) V = 0.0 Volts E) V = -6.0 Volts Point P V R A R B I bat I A I B P1 P2 P3 P4 P5 Position In Loop Voltage 1 2 3 4 5 1 6V 4.5V 3.0V 1.5V 0.0V Define V=0 at P1. Resistors in Series: Example
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Clicker Question We start with the left circuit with one lightbulb (A). The brightness of the bulb directly reflects the power. If we add a second bulb (B) as shown on the right, what happens to the bulbs? V A V A B A)Bulb A is equally bright. B)Bulb A is dimmer than before C)Bulb A is brighter than before Two light bulbs, A and B, are in series, so they carry the same current. Light bulb A is brighter than B. Which bulb has higher resistance? A) A B) B C) Same resistance. V A B Answer: Bulb A has higher resistance. Since the resistors are in series, they have the same current I. According to P = I 2 R, if I = constant, then higher R gives higher P. Clicker Question
Background image of page 6
Clicker Question If we connect a battery with V = 6 Volts with three resistors R1 = 10 , R2 = 20 , R3 = 30 , which of the following is true?
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 25

chapter26 - Electric circuit components Capacitor stores...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online