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STEM Cloud · Physics

G.C.E. O/L Physics · Grade 11

Power and Energy of Electric Appliancesமின் உபகரணங்களோட வலுவும் சக்தியும்විදුලි උපකරණවල ජවය හා ශක්තිය

மின் உபகரணங்களோட வலுவும் சக்தியும்විදුලි උපකරණවල ජවය හා ශක්තිය

Household wiring, earthing, fuses, circuit breakers, power consumption, and safety. This page is a free preview of the STEM Cloud lesson for Grade 11 G.C.E. Ordinary Level Physics in Sri Lanka: the key points, the formulas, a worked example and a short quiz, taken from the lesson itself.

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What you will learn

  • Energy conversions in appliancesஉபகரணங்கள்ல சக்தி மாற்றங்கள்උපකරණවල ශක්ති පරිවර්තන
  • Power of an appliance: P = V Iஉபகரணத்தோட வலு: P = V Iඋපකරණයක ජවය: P = V I
  • Electric energy used: E = P tபயன்படுத்திய மின் சக்தி: E = P tභාවිතා වන විදුලි ශක්තිය: E = P t
  • Efficiency and saving energyதிறனும் சக்தி சேமிப்பும்කාර්යක්ෂමතාව සහ ශක්තිය ඉතිරි කිරීම
  • The home electric circuitவீட்டு மின்சுற்றுගෘහස්ථ විදුලි පරිපථය
  • The kilowatt hourகிலோவாட் மணிකිලෝවොට් පැය

Key points to remember

  • The power of an electric appliance is the electric energy used per unit time.
    மின் உபகரணத்தோட வலு என்பது ஓரலகு நேரத்துல பயன்படுத்தற மின் சக்தி.
    විද්‍යුත් උපකරණයක ජවය යනු ඒකක කාලයකට භාවිතා වන විදුලි ශක්තියයි.
  • Power P = V I (watts); energy E = P t = V I t (joules).
    வலு P = V I (வாட்); சக்தி E = P t = V I t (ஜூல்).
    ජවය P = V I (වොට්); ශක්තිය E = P t = V I t (ජූල්).
  • The domestic meter measures energy in kilowatt hours; 1 kW h = 3 600 000 J.
    வீட்டு மீற்றர் சக்திய கிலோவாட் மணில அளக்கும்; 1 kW h = 3 600 000 J.
    ගෘහස්ථ මීටරය ශක්තිය මනින්නේ කිලෝවොට් පැයවලිනි; 1 kW h = 3 600 000 J.
  • Efficient appliances (LED, CFL, immersion heaters, induction cookers) save energy.
    திறனான உபகரணங்கள் (LED, CFL, அமிழ்ப்பு வெப்பமாக்கி, தூண்டற் சமைகலன்) சக்திய சேமிக்கும்.
    කාර්යක්ෂම උපකරණ (LED, CFL, ගිල්ලුම් තාපක, ප්‍රේරක උදුන්) ශක්තිය ඉතිරි කරයි.
  • House supply: 230 V, 50 Hz alternating current, through a live and a neutral wire.
    வீட்டு வழங்கல்: 230 V, 50 Hz மாறுதிசை மின்னோட்டம், உயிர், நொதுமல் கம்பிகள் வழியா.
    නිවසේ සැපයුම: 230 V, 50 Hz ප්‍රත්‍යාවර්ත ධාරාව, සජීවී සහ උදාසීන කම්බි දෙකක් හරහා.
  • The RCCB protects people from shock; MCBs and fuses protect the circuits from large currents.
    RCCB மனிதர்கள மின்னதிர்ச்சில இருந்து காக்கும்; MCB, உருகிகள் சுற்றுகள அதிக மின்னோட்டத்துல இருந்து காக்கும்.
    RCCB මිනිසුන් කම්පනයෙන් ආරක්ෂා කරයි; MCB සහ විලායක පරිපථ විශාල ධාරාවලින් ආරක්ෂා කරයි.
  • Bulbs and sockets are in parallel; switches, fuses and MCBs are on the live wire.
    குமிழ்கள், குதைகள் சமாந்தரம்; சுவிட்சுகள், உருகிகள், MCB உயிர் கம்பில.
    බල්බ සහ කෙවෙනි සමාන්තරයි; ස්විච, විලායක සහ MCB සජීවී කම්බියේ ඇත.

Key formulas

Electric powerமின் வலுවිදුලි ජවය

மின் வலுවිදුලි ජවය

P = V I

  • P = powerவலுජවය (W)
  • V = potential differenceஅழுத்த வித்தியாசம்විභව අන්තරය (V)
  • I = currentமின்னோட்டம்ධාරාව (A)

An iron on 230 V draws 2 A: P = 230 × 2 = 460 W230 V இல் அழுத்தி 2 A எடுக்கிறது: P = 230 × 2 = 460 W230 V මත ඉස්ත්‍රික්කයක් 2 A ගනී: P = 230 × 2 = 460 W

Choosing a fuseஉருகியைத் தேர்ந்தெடுத்தல்විලායකය තෝරා ගැනීම

உருகியைத் தேர்ந்தெடுத்தல்විලායකය තෝරා ගැනීම

I = P ÷ V

  • I = currentமின்னோட்டம்ධාරාව (A)
  • P = powerவலுජවය (W)
  • V = potential differenceஅழுத்த வித்தியாசம்විභව අන්තරය (V)

A 2000 W oven on 230 V: I = 2000 ÷ 230 = 8.70 A, so it needs a 13 A fuse230 V இல் 2000 W அடுப்பு: I = 2000 ÷ 230 = 8.70 A, அதனால 13 A உருகி வேணும்230 V මත 2000 W උදුනක්: I = 2000 ÷ 230 = 8.70 A, එබැවින් 13 A විලායකයක් අවශ්‍යයි

Electric energyமின் சக்திවිදුලි ශක්තිය

மின் சக்திවිදුලි ශක්තිය

E = P t = V I t

  • E = energyசக்திශක්තිය (J)
  • P = powerவலுජවය (W)
  • t = timeநேரம்කාලය (s)

A 1000 W kettle for 60 s: E = 1000 × 60 = 60 000 J1000 W கேத்தல் 60 s: E = 1000 × 60 = 60 000 J1000 W කේතලයක් 60 s: E = 1000 × 60 = 60 000 J

Efficiencyதிறன்කාර්‍යක්ෂමතාව

திறன்කාර්‍යක්ෂමතාව

[object Object]

    A bulb is supplied with 100 J and gives 15 J of light: (15 ÷ 100) × 100 % = 15 %100 J வழங்கப்பட்ட குமிழ் 15 J ஒளி தருது: (15 ÷ 100) × 100 % = 15 %ජූල් 100 ක් සපයන බල්බයක් ජූල් 15 ක ආලෝකයක් දෙයි: (15 ÷ 100) × 100 % = 15 %

    Units of electricity (kW h)மின் அலகுகள் (kW h)විදුලි ඒකක (kW h)

    மின் அலகுகள் (kW h)විදුලි ඒකක (kW h)

    [object Object]

      A 100 W bulb for 10 hours: (100 ÷ 1000) × 10 = 1 unit100 W குமிழ் 10 மணி: (100 ÷ 1000) × 10 = 1 அலகு100 W බල්බයක් පැය 10 ක්: (100 ÷ 1000) × 10 = ඒකක 1

      A worked example

      Textbook example · Ch.10, p.33பாடப்புத்தக உதாரணம் · பாடம் 10, ப.33පෙළපොත් නිදසුන · 10 පරි., පි.33

      A filament bulb on 12 V draws 2 A. What is its power?
      Step 1

      P = V I.

      Step 2

      P = 12 × 2.

      Final answer: 24 W.
      12 V-ல இயங்கும் இழைக் குமிழ் 2 A எடுக்குது. அதோட வலு?
      படி 1தொடு, பாரு!

      P = V I.

      படி 2தொடு, பாரு!

      P = 12 × 2.

      இறுதி விடை: 24 W.
      12 V මත ඇති සූතිකා බල්බයක් 2 A ඇදගනී. එහි ජවය කොපමණද?
      පියවර 1පෙන්වීමට ස්පර්ශ කරන්න

      P = V I.

      පියවර 2පෙන්වීමට ස්පර්ශ කරන්න

      P = 12 × 2.

      අවසාන පිළිතුර: 24 W.

      Try 5 quiz questions

      1. A bulb works on 12 V and draws 2 A. What is its power?12 V-ல இயங்கும் ஒரு குமிழ் 2 A எடுக்குது. அதோட வலு?බල්බයක් 12 V මත ක්‍රියා කර 2 A ඇදගනී. එහි ජවය කොපමණද?

        • A 6 W6 W
        • B 14 W14 W
        • C 24 W24 W
        • D 0.17 W0.17 W
        Show the answer

        Answer: C. 24 W24 W

        P = V I = 12 × 2 = 24 W.P = V I = 12 × 2 = 24 W.

      2. A 2000 W oven works on 230 V. What current does it draw?2000 W அடுப்பு 230 V-ல இயங்குது. அது எடுக்கும் மின்னோட்டம்?

        • A 0.115 A0.115 A
        • B 8.70 A8.70 A
        • C 460 A460 A
        • D 2230 A2230 A
        Show the answer

        Answer: B. 8.70 A8.70 A

        I = P ÷ V = 2000 ÷ 230 = 8.70 A.I = P ÷ V = 2000 ÷ 230 = 8.70 A.

      3. Which formula gives the electric energy used?பயன்படுத்திய மின் சக்திய தரும் சூத்திரம் எது?

        • A E = P ÷ tE = P ÷ t
        • B E = P tE = P t
        • C E = V ÷ IE = V ÷ I
        • D E = I ÷ tE = I ÷ t
        Show the answer

        Answer: B. E = P tE = P t

        E = P t = V I t.E = P t = V I t.

      4. How many joules are there in 1 kW h?1 kW h-ல எத்தனை ஜூல்?

        • A 1000 J1000 J
        • B 3600 J3600 J
        • C 3.6 × 10⁶ J3.6 × 10⁶ J
        • D 3.6 × 10⁹ J3.6 × 10⁹ J
        Show the answer

        Answer: C. 3.6 × 10⁶ J3.6 × 10⁶ J

        1 kW h = 1000 W × 3600 s = 3 600 000 J.1 kW h = 1000 W × 3600 s = 3 600 000 J.

      5. Which device protects people from electric shock?எந்த சாதனம் மனிதர்கள மின்னதிர்ச்சில இருந்து காக்கும்?

        • A A fuseஉருகிවිලායකයක්
        • B An MCBMCBMCB එකක්
        • C An RCCB (trip switch)RCCB (ட்ரிப் சுவிட்ச்)RCCB එකක් (පැන්නුම් ස්විචය)
        • D The electricity meterமின் மீற்றர்විදුලි මීටරය
        Show the answer

        Answer: C. An RCCB (trip switch)RCCB (ட்ரிப் சுவிட்ச்)RCCB එකක් (පැන්නුම් ස්විචය)

        The RCCB cuts the supply when current leaks. Fuses and MCBs protect the wires only.மின் கசிவு ஏற்பட்டா RCCB மின்சாரத்த துண்டிக்கும். உருகிகள், MCB கம்பிகள மட்டும் காக்கும்.ධාරාව කාන්දු වූ විට RCCB සැපයුම කපා හරියි. විලායක සහ MCB ආරක්ෂා කරන්නේ කම්බි පමණි.

      In Tamil and Sinhala · தமிழில் · සිංහලෙන්

      Every STEM Cloud lesson is in Tamil, English and Sinhala. The chapter's words, as the lesson uses them:

      மின் உபகரணத்தோட வலு என்பது ஓரலகு நேரத்துல பயன்படுத்தற மின் சக்தி.

      විද්‍යුත් උපකරණයක ජවය යනු ඒකක කාලයකට භාවිතා වන විදුලි ශක්තියයි.

      • Power · வலு · ක්ෂමතාව (ජවය)
      • Efficiency · திறன் · කාර්යක්ෂමතාව
      • Hot plate · வெப்பத் தட்டு · තාපන ඵලකය
      • Immersion heater · அமிழ்ப்பு வெப்பமாக்கி · ගිල්ලුම් තාපකය
      • Microwave oven · நுண்ணலை அடுப்பு · ක්ෂුද්‍ර තරංග උදුන
      • Induction cooker · தூண்டற் சமைகலன் · ප්‍රේරක උදුන
      • Live · உயிர் · සජීවී
      • Neutral · நொதுமல் · උදාසීන
      • Fuse · உருகி · විලායකය
      • Residual current circuit breaker · RCCB (ட்ரிப் சுவிட்ச்) · ශේෂ ධාරා පරිපථ බිඳිනය
      • Distribution box · பரப்பற் பெட்டி · විබෙදුම් පෙට්ටිය
      • Miniature circuit breaker · MCB · සිහිති පරිපථ බිඳිනය
      • Plug socket · குதை · කෙවෙනිය
      • Plug · செருகி · පේනුව
      • Overload circuit breaker · அதிகச் சுமை சுற்றுடைப்பான் · අධිධාරා පරිපථ බිඳිනය
      • Isolator · பிரதான ஆளி · වෙන්කරණය
      • Watt · வாட் · වොට්
      • Joule · ஜூல் · ජූලය
      • Kilowatt hour · கிலோவாட் மணி · කිලෝවොට් පැය
      • Unit (of electricity) · அலகு · ඒකකය (විදුලි)
      • Earth wire · நிலக் கம்பி · භූගත කම්බිය
      • Earthing · நிலத்தொடுப்பு · භූගත කිරීම
      • Double insulation · இரட்டைக் காப்பு · ද්විත්ව පරිවරණය

      In the full lesson

      The full Power and Energy of Electric Appliances lesson walks through every step: the cartoon animation, the notes, all 5 worked examples, the virtual lab, the games and all 8 quiz questions. It opens with an account.

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      Questions about Power and Energy of Electric Appliances

      Is Power and Energy of Electric Appliances in the G.C.E. O/L Physics syllabus?

      Yes. Power and Energy of Electric Appliances is a Grade 11 unit of G.C.E. Ordinary Level Physics in Sri Lanka, and STEM Cloud teaches it in the same order as the course map.

      What are the key points of Power and Energy of Electric Appliances?

      The power of an electric appliance is the electric energy used per unit time. Power P = V I (watts); energy E = P t = V I t (joules). The domestic meter measures energy in kilowatt hours; 1 kW h = 3 600 000 J.

      Can I study Power and Energy of Electric Appliances in Tamil or Sinhala?

      Yes. Every STEM Cloud lesson is in Tamil, English and Sinhala, and you can switch the language at any time from the lesson header.

      How do I get the full Power and Energy of Electric Appliances lesson?

      Sign up on the sign-up page, or message the admin on WhatsApp at 077 676 8865. You can try a free lesson first: Motion in a Straight Line.