1. Agenda Bell Work
• Notes: Electric Power
• Calculations • What is the difference
between a series and a
parallel circuit?
• Household Energy Use –
• When more devises (light
Gizmo
bulbs) are added to each,
what happens to:
• HW: Chp 12 pg 192-195, – Voltage
204 – Currant
– resistance
• Test Friday

2. November 26, 2012

3. 1. Explain how moving electrons can do work
2. Calculate Power given two variables

4.  Moving charges can do work – heat a circuit or
turn a motor
 Power is the rate of using energy

5.  Electrical energy may be transformed to:
 Mechanical energy (a motor)
 Light (a lamp)
 Thermal energy (a heater)
 or other forms

6.  Power = current x voltage
 Units
 Watts = amperes x volts
What power is needed to operate a clock radio if it
draws a current of 0.05 amps from your household
circuit?

9.  Electrical Energy is supplied to our houses by
generators and motors
 This energy is purchased from power company’s
 The electrical energy travels through power lines to
individual homes to be sold to the homeowner

10.  The units of energy sold is represented in units
of 1000 watts delivered for one hour, or units
called kilowatt-hours.
 1 kilowatt = 1000 watts
 1 kilowatt-hour = 1000 watts delivered for 1
hour
 The more electrical power a consumer
demands, the more kilowatts are used