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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 403 · 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 of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) run fans in empty rooms (d) leave fridge door open
  2. 2.Which of these wastes electricity? (a) use LED lamps (b) unplug idle chargers (c) close the fridge quickly (d) run fans in empty rooms
  3. 3.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
  4. 4.🔍 Which is the odd one out? (a) leave the TV on standby (b) use old filament bulbs (c) leave fridge door open (d) unplug idle chargers
  5. 5.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  6. 6.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  7. 7.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
  8. 8.True or false: to leave fridge door open wastes electricity. (a) True (b) False
  9. 9.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  10. 10.Which of these saves electricity? (a) use old filament bulbs (b) set the AC to 24 °C (c) leave fridge door open (d) leave the TV on standby
  11. 11.Which of these wastes electricity? (a) switch off empty rooms (b) leave the TV on standby (c) use LED lamps (d) unplug idle chargers
  12. 12.True or false: to use old filament bulbs saves electricity. (a) False (b) True
  13. 13.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  14. 14.Which of these saves electricity? (a) iron one shirt at a time (b) switch off empty rooms (c) run fans in empty rooms (d) use old filament bulbs
  15. 15.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  16. 16.🧾 A family uses 90 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  17. 17.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
  18. 18.🔍 Which is the odd one out? (a) leave fridge door open (b) use daylight to read (c) switch off empty rooms (d) close the fridge quickly
  19. 19.True or false: to use daylight to read saves electricity. (a) False (b) True
  20. 20.🔍 Which is the odd one out? (a) switch off empty rooms (b) iron one shirt at a time (c) close the fridge quickly (d) unplug idle chargers
  21. 21.Which of these saves electricity? (a) leave the TV on standby (b) use daylight to read (c) iron one shirt at a time (d) use old filament bulbs
  22. 22.True or false: to switch off empty rooms saves electricity. (a) False (b) True
  23. 23.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
  24. 24.🧾 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?
  25. 25.Which of these wastes electricity? (a) switch off empty rooms (b) use LED lamps (c) unplug idle chargers (d) iron one shirt at a time
  26. 26.True or false: to use daylight to read wastes electricity. (a) True (b) False
  27. 27.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) switch off empty rooms (d) run fans in empty rooms
  28. 28.True or false: to unplug idle chargers saves electricity. (a) True (b) False
  29. 29.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
  30. 30.🧾 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?
  31. 31.🧾 A family uses 40 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  32. 32.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  33. 33.True or false: to leave the TV on standby saves electricity. (a) True (b) False
  34. 34.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  35. 35.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  36. 36.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  37. 37.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  38. 38.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  39. 39.🧾 A family uses 200 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  40. 40.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False

Answer key

  1. use LED lamps
  2. run fans in empty rooms
  3. an LED lamp
  4. unplug idle chargers
  5. saves electricity
  6. saves electricity
  7. True
  8. True
  9. 2
  10. set the AC to 24 °C
  11. leave the TV on standby
  12. False
  13. False
  14. switch off empty rooms
  15. saves electricity
  16. 360
  17. 1 kilowatt-hour (kWh)
  18. leave fridge door open
  19. True
  20. iron one shirt at a time
  21. use daylight to read
  22. True
  23. wastes electricity
  24. 441
  25. iron one shirt at a time
  26. False
  27. switch off empty rooms
  28. True
  29. False
  30. 408
  31. 200
  32. 160
  33. False
  34. 153
  35. 189
  36. wastes electricity
  37. False
  38. 6
  39. 1200
  40. False

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