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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 670 · 40 questions
TalentJR

Remember (Watts × hours ÷ 1000): Units (kWh) = watts × hours ÷ 1000. Bill = units × price per unit (e.g. 150 units × ₹6 = ₹900). Save: switch off, LED lamps, daylight, no standby, close the fridge quickly.

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  1. 1.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) run fans in empty rooms (d) use daylight to read
  2. 2.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  3. 3.Which of these wastes electricity? (a) unplug idle chargers (b) run fans in empty rooms (c) close the fridge quickly (d) use daylight to read
  4. 4.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  5. 5.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use daylight to read (c) switch off empty rooms (d) set the AC to 24 °C
  6. 6.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) a filament bulb (d) an LED lamp
  7. 7.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  8. 8.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) run fans in empty rooms (d) use LED lamps
  9. 9.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
  10. 10.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  11. 11.Which of these wastes electricity? (a) switch off empty rooms (b) leave the TV on standby (c) set the AC to 24 °C (d) use daylight to read
  12. 12.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
  13. 13.Which of these wastes electricity? (a) use LED lamps (b) unplug idle chargers (c) leave fridge door open (d) set the AC to 24 °C
  14. 14.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) iron one shirt at a time (d) use daylight to read
  15. 15.🔍 Which is the odd one out? (a) switch off empty rooms (b) leave fridge door open (c) use LED lamps (d) close the fridge quickly
  16. 16.🧾 A family uses 190 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  17. 17.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  18. 18.True or false: to use daylight to read saves electricity. (a) True (b) False
  19. 19.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  20. 20.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) close the fridge quickly (d) use old filament bulbs
  21. 21.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  22. 22.True or false: to switch off empty rooms saves electricity. (a) True (b) False
  23. 23.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  24. 24.🧾 A family uses 90 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  25. 25.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  26. 26.🧾 A family uses 30 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  27. 27.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  28. 28.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
  29. 29.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  30. 30.Which of these saves electricity? (a) iron one shirt at a time (b) use old filament bulbs (c) leave fridge door open (d) set the AC to 24 °C
  31. 31.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False
  32. 32.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  33. 33.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
  34. 34.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  35. 35.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  36. 36.Which of these wastes electricity? (a) close the fridge quickly (b) switch off empty rooms (c) use old filament bulbs (d) use daylight to read
  37. 37.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
  38. 38.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  39. 39.🧾 A family uses 120 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  40. 40.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?

Answer key

  1. use daylight to read
  2. saves electricity
  3. run fans in empty rooms
  4. 441
  5. iron one shirt at a time
  6. an LED lamp
  7. 0.25
  8. use LED lamps
  9. 1 kilowatt-hour (kWh)
  10. 160
  11. leave the TV on standby
  12. saves electricity
  13. leave fridge door open
  14. iron one shirt at a time
  15. leave fridge door open
  16. 950
  17. 63
  18. True
  19. wastes electricity
  20. close the fridge quickly
  21. saves electricity
  22. True
  23. 2
  24. 810
  25. wastes electricity
  26. 270
  27. saves electricity
  28. True
  29. 15
  30. set the AC to 24 °C
  31. True
  32. 459
  33. False
  34. False
  35. saves electricity
  36. use old filament bulbs
  37. True
  38. 1
  39. 1080
  40. 408

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