Survey

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Nanofluidic circuitry wikipedia, lookup

Superconducting magnet wikipedia, lookup

Energy applications of nanotechnology wikipedia, lookup

Electromigration wikipedia, lookup

Carbon nanotubes in interconnects wikipedia, lookup

Electricity wikipedia, lookup

Scanning SQUID microscope wikipedia, lookup

Transcript
```Circuit Electricity
May 30, 2012
Chapter 22
Terms

Current: Flow of charge


Symbolized by “I”
Units = Coulombs/second = Amperes (A)
Circuit: a closed loop that current flows
through
 Resistance: Opposition to current



Units = Ohms (Ω)
LED: Light Emitting Diode

Used to test for presence of current.
More Terms
Volts: the force that pushes current through a
circuit
 Power: the energy delivered to the circuit per
second




Power = (current)(voltage)
P = (I)(V)
Units = Watts
Examples #1 & #2
A
car battery causes a current of 2.0
amps through a light while 12 V is across
the battery. What is the power used by
the lamp?
P = (2.0)(12)
 P = 24 W
 What is the current through a 75W lightbulb
connected to a 120 V outlet?
 75 = (I)(120)
 I = .625 A

How does a light bulb light?
As the current flows through the filament, it
encounters resistance
 Resistance: a material’s opposition to current
flow
 Ohm’s Law:



R = (V/I)
 As resistance increases, current decreases
 As voltage increases, current increases
The collisions between the current and
material results in energy loss (heat and light)
Examples #3 & #4

A car headlight has a resistance of 30Ω and is hooked to
a 12V battery. What is the current through the bulb?



30 = (12/I)
I = (12/30) = .40 A
A lamp draws a current of .50A when connected to a
120-V outlet. What is the resistance of the lamp?


R = (120/.50)
R = 240 Ω
Homework



Ch 22
p 527-529
# 22,23,25,27,30,33,42,45
```
Related documents