1 / 10

Understanding Electrical Power: Basics, Equations, and Household Examples

This guide dives into the fundamentals of electrical power, introducing key concepts such as resistance, current, and voltage. It explains how power is defined as energy over time, using the units of joules and watts. You'll learn the relationships between power, current, and potential difference through essential equations. Additionally, it provides practical examples of power ratings for common household appliances, helping you calculate current in amps. Discover how efficiency plays a role in device performance, underscoring that perfection is unattainable in energy conversion.

lise
Télécharger la présentation

Understanding Electrical Power: Basics, Equations, and Household Examples

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. P O W E R

  2. Remember when…… • Let’s take a brief step back….

  3. But first… • Resistance = charge / current • Resistance = volts / amps • So … charge = resistance X current • current = charge / resistance • resistance = charge / current

  4. What is POWER? • Power is defined as • Units of Energy / Time • Electrical Power - the amount of electrical power converted to heat, light, sound or motion every second. • Electrical Power - the amount of electrical energy transmitted in a given unit of time.

  5. Symbols of Power • The symbol for power is P • P = energy / time • P = E/T • Energy is measured in joules • P = joules/second • P = watts

  6. The Watt • Named in honour of James Watt (1736-1819) • 1 joule of electrical energy is converted into light and heat by a light bulb every second the power of the bulb is 1 watt. • 60 joules per second is 60 watts

  7. Using the equation… • P = E / t • V (potential difference)= E (energy) / Q (unit of charge) • V = E /Q • E = QxV or just QV • P = E / t becomes P = • We know that is current (or I) …so • P = IV Power = Current x Potential Difference • Remember = power is measured in watts QV t Q t

  8. What you really need to know… • Power (watts) = Current (amps) x Potential (volts) • A current of 13.6 A passes thr ough an electric baseboard heater when it is connected to a 110 V wall outlet. What is the power of the heater? • I = 13.6 • V = 110 V • P = IV = 13.6 x 110 • P = 1496 watts or • P = 1.5 x 103 watts

  9. Power Ratings • Some common household examples in watts: • Hair dryer .................................... 1600 • Deep Fryer ................................. 1500 • Portable Heater .......................... 1500 • Iron ............................................. 1000 • Vacuum Cleaner.......................... 600 • Portable Fan................................. 150 • Television .................................... 150 • Computer ..................................... 150 • VCR............................................... 40 • Stereo ........................................... 30 • Light bulbs.................. 40, 60, 75 or 100 Calculate the current in amps for these appliances P(w) = IV I(a) = P / V V(v) = P / I

  10. Nobody’s Perfect • No device is perfect • Some energy is always converted to heat • Some energy always escapes to the outside • We can calculate efficiency of an appliance • Efficiency % = (energy out / energy in) x100

More Related