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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 860 · 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 lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) an oil lamp (d) a candle
  2. 2.🧾 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?
  3. 3.Which of these wastes electricity? (a) set the AC to 24 °C (b) leave fridge door open (c) use LED lamps (d) use daylight to read
  4. 4.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  5. 5.Which of these wastes electricity? (a) run fans in empty rooms (b) unplug idle chargers (c) use LED lamps (d) use daylight to read
  6. 6.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  7. 7.Which of these saves electricity? (a) run fans in empty rooms (b) use daylight to read (c) leave fridge door open (d) use old filament bulbs
  8. 8.True or false: to leave fridge door open wastes electricity. (a) True (b) False
  9. 9.🧾 A family uses 60 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  10. 10.Which of these saves electricity? (a) run fans in empty rooms (b) close the fridge quickly (c) iron one shirt at a time (d) leave fridge door open
  11. 11.🧾 A family uses 100 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  12. 12.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  13. 13.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  14. 14.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  15. 15.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  16. 16.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  17. 17.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  18. 18.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  19. 19.🔍 Which is the odd one out? (a) use old filament bulbs (b) use daylight to read (c) switch off empty rooms (d) set the AC to 24 °C
  20. 20.🧾 A family uses 90 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  21. 21.🧾 A family uses 130 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  22. 22.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  23. 23.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) use old filament bulbs (d) unplug idle chargers
  24. 24.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  25. 25.Which of these saves electricity? (a) leave fridge door open (b) iron one shirt at a time (c) run fans in empty rooms (d) set the AC to 24 °C
  26. 26.🧾 A family uses 170 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  27. 27.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave fridge door open (c) run fans in empty rooms (d) use daylight to read
  28. 28.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  29. 29.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 ampere
  30. 30.Which of these saves electricity? (a) switch off empty rooms (b) iron one shirt at a time (c) leave the TV on standby (d) leave fridge door open
  31. 31.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  32. 32.True or false: to use daylight to read wastes electricity. (a) False (b) True
  33. 33.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  34. 34.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  35. 35.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
  36. 36.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
  37. 37.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
  38. 38.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  39. 39.🧾 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?
  40. 40.True or false: to leave the TV on standby wastes electricity. (a) False (b) True

Answer key

  1. an LED lamp
  2. 408
  3. leave fridge door open
  4. saves electricity
  5. run fans in empty rooms
  6. saves electricity
  7. use daylight to read
  8. True
  9. 300
  10. close the fridge quickly
  11. 800
  12. saves electricity
  13. False
  14. 0.8
  15. 0.5
  16. saves electricity
  17. 0.3
  18. 340
  19. use old filament bulbs
  20. 720
  21. 650
  22. wastes electricity
  23. unplug idle chargers
  24. 0.2
  25. set the AC to 24 °C
  26. 680
  27. use daylight to read
  28. 238
  29. 1 kilowatt-hour (kWh)
  30. switch off empty rooms
  31. 136
  32. False
  33. 15
  34. 2.5
  35. wastes electricity
  36. False
  37. True
  38. 16
  39. 459
  40. True

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