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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 959 · 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.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  2. 2.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  3. 3.Which of these wastes electricity? (a) use daylight to read (b) leave fridge door open (c) unplug idle chargers (d) set the AC to 24 °C
  4. 4.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  5. 5.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  6. 6.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  7. 7.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
  8. 8.🔍 Which is the odd one out? (a) close the fridge quickly (b) leave the TV on standby (c) use old filament bulbs (d) iron one shirt at a time
  9. 9.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) an oil lamp (c) a filament bulb (d) a candle
  10. 10.🧾 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?
  11. 11.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  12. 12.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  13. 13.True or false: to iron one shirt at a time saves electricity. (a) False (b) True
  14. 14.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
  15. 15.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  16. 16.🧾 A family uses 200 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  17. 17.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) use LED lamps (d) leave fridge door open
  18. 18.🧾 A family uses 50 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  19. 19.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) iron one shirt at a time (d) close the fridge quickly
  20. 20.🧾 A family uses 140 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  21. 21.🔍 Which is the odd one out? (a) use LED lamps (b) leave the TV on standby (c) run fans in empty rooms (d) use old filament bulbs
  22. 22.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
  23. 23.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  24. 24.Which of these saves electricity? (a) use old filament bulbs (b) iron one shirt at a time (c) leave the TV on standby (d) unplug idle chargers
  25. 25.🧾 A family uses 40 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  26. 26.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  27. 27.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  28. 28.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  29. 29.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  30. 30.🧾 A family uses 60 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  31. 31.🧾 A family uses 80 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  32. 32.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  33. 33.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
  34. 34.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  35. 35.True or false: to switch off empty rooms saves electricity. (a) False (b) True
  36. 36.Which of these saves electricity? (a) close the fridge quickly (b) leave fridge door open (c) leave the TV on standby (d) use old filament bulbs
  37. 37.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  38. 38.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  39. 39.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
  40. 40.🧾 A family uses 60 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?

Answer key

  1. 255
  2. 0.2
  3. leave fridge door open
  4. wastes electricity
  5. 567
  6. wastes electricity
  7. 306
  8. close the fridge quickly
  9. an LED lamp
  10. 408
  11. saves electricity
  12. saves electricity
  13. False
  14. True
  15. 0.4
  16. 800
  17. use LED lamps
  18. 400
  19. iron one shirt at a time
  20. 560
  21. use LED lamps
  22. 1 kilowatt-hour (kWh)
  23. 272
  24. unplug idle chargers
  25. 280
  26. 6
  27. False
  28. True
  29. 3
  30. 360
  31. 480
  32. 5
  33. True
  34. wastes electricity
  35. True
  36. close the fridge quickly
  37. False
  38. 6
  39. False
  40. 420

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