ArtsAutosBooksBusinessEducationEntertainmentFamilyFashionFoodGamesGenderHealthHolidaysHomeHubPagesPersonal FinancePetsPoliticsReligionSportsTechnologyTravel

How much Power Dissipate Or Loss In Resistors?

Updated on August 6, 2010
Figure (1)
Figure (1)

Today I got the honor to write over quite interesting and important topic of electrical engineering i.e. “Power dissipation in resistors”. Before going into the topic we should know the basic terminologies used in above prescribed article.


Power is defined as rate of transforming energy from one form to another form. The S.I. unit for it is Watt.


A resistor is a passive component of a circuit that resists the flow of electrical current. The S.I. unit for resistor is Ohm.

Now we can go towards our main article. The above mentioned definitions will be quite beneficial in understanding the article clearly. We can derive the relation that how much a certain power dissipated across the resistor with the help of figure (1).When the current is flowing through high resistance electric appliances like bulb, heater and electric iron the energy lost by the electrons at the time of collision appears in the form of light and heat. The relation for power loss across a resistor is derived as follow:

Let a charge ‘Q’is made to pass through a resistor AB such that the voltage across its two ends is ‘V’, in ‘t’ time. The energy lost bythe charge Q while passing through the resistor is ‘VQ’. This energy is taken by the atoms of the resistor and so increases their temperature.

i.e. Energy = V Q

Time = t

But from above we know that power is transformation of energy or rate of change or energy or rate of loss of energy so

                                                       Power = Energy / time

                                                              P = V Q / t


                                                            Q/ t = I (Electric Current)


                                                             P = V I (I)

But also by Ohm’s Law

                                                             V = I R (II)

So (I) becomes

                                                            P = I R * I

                                                            P = I2R (III)

Also by Ohm’sLaw

                                                            I = V / R

So (II) becomes

                                                            P =(V / R)2 * R

                                                            P =V2 / R2 * R

                                                            P = V2 / R (IV)

Equation (IV)describes the amount of power dissipated across certain resistor. For example if ‘2’ Ampere of current is applied across the resistor of ‘5’ ohm, then the power dissipated across the resistor can be calculated using above equations.Equation (II) gives the value of voltage i.e. 10 Volts, further using equation(IV) we can calculate the amount of power loss i.e. 20 watt.


    0 of 8192 characters used
    Post Comment

    • profile image


      6 years ago

      thanks really good job. it helped me.

    • awnmuhammad1 profile imageAUTHOR


      8 years ago from Pakistan

      @Peter... thanks for appreciating my work

    • profile image

      Peter Enmore 

      8 years ago

      Thanks for including a diagram in your hub. Most people don't, and I think a visual really helps. Especially when it comes to this sort of subject.

    • profile image


      8 years ago

      Hey that's really informative......


    This website uses cookies

    As a user in the EEA, your approval is needed on a few things. To provide a better website experience, uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

    For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at:

    Show Details
    HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
    LoginThis is necessary to sign in to the HubPages Service.
    Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
    AkismetThis is used to detect comment spam. (Privacy Policy)
    HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
    HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
    Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
    CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
    Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the or domains, for performance and efficiency reasons. (Privacy Policy)
    Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
    Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
    Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
    Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
    Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
    VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
    PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
    Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
    MavenThis supports the Maven widget and search functionality. (Privacy Policy)
    Google AdSenseThis is an ad network. (Privacy Policy)
    Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
    Index ExchangeThis is an ad network. (Privacy Policy)
    SovrnThis is an ad network. (Privacy Policy)
    Facebook AdsThis is an ad network. (Privacy Policy)
    Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
    AppNexusThis is an ad network. (Privacy Policy)
    OpenxThis is an ad network. (Privacy Policy)
    Rubicon ProjectThis is an ad network. (Privacy Policy)
    TripleLiftThis is an ad network. (Privacy Policy)
    Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
    Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
    Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
    Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
    ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
    Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)