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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 789 · 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.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  2. 2.🧾 A family uses 120 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  3. 3.🧾 A family uses 200 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  4. 4.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) leave fridge door open (d) switch off empty rooms
  5. 5.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  6. 6.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  7. 7.Which of these wastes electricity? (a) use LED lamps (b) use old filament bulbs (c) use daylight to read (d) switch off empty rooms
  8. 8.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) switch off empty rooms (d) close the fridge quickly
  9. 9.True or false: to use LED lamps saves electricity. (a) False (b) True
  10. 10.🧾 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?
  11. 11.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  12. 12.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  13. 13.🧾 A family uses 170 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  14. 14.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
  15. 15.Which of these saves electricity? (a) leave fridge door open (b) use daylight to read (c) leave the TV on standby (d) use old filament bulbs
  16. 16.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  17. 17.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  18. 18.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) iron one shirt at a time (d) use daylight to read
  19. 19.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  20. 20.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) unplug idle chargers (d) run fans in empty rooms
  21. 21.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  22. 22.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  23. 23.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) a candle (d) an LED lamp
  24. 24.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave the TV on standby (c) run fans in empty rooms (d) set the AC to 24 °C
  25. 25.True or false: to use LED lamps wastes electricity. (a) False (b) True
  26. 26.🔍 Which is the odd one out? (a) unplug idle chargers (b) use old filament bulbs (c) close the fridge quickly (d) use LED lamps
  27. 27.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  28. 28.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
  29. 29.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  30. 30.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  31. 31.🧾 A family uses 60 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  32. 32.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  33. 33.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) run fans in empty rooms (d) switch off empty rooms
  34. 34.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  35. 35.🧾 A family uses 90 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  36. 36.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) leave the TV on standby (d) unplug idle chargers
  37. 37.🧾 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?
  38. 38.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  39. 39.True or false: to use daylight to read saves electricity. (a) True (b) False
  40. 40.True or false: to leave the TV on standby wastes electricity. (a) True (b) False

Answer key

  1. False
  2. 600
  3. 1400
  4. leave fridge door open
  5. wastes electricity
  6. 126
  7. use old filament bulbs
  8. run fans in empty rooms
  9. True
  10. 272
  11. True
  12. 2.5
  13. 680
  14. 1 kilowatt-hour (kWh)
  15. use daylight to read
  16. 8
  17. 300
  18. use daylight to read
  19. 0.2
  20. run fans in empty rooms
  21. 850
  22. False
  23. an LED lamp
  24. set the AC to 24 °C
  25. False
  26. use old filament bulbs
  27. saves electricity
  28. wastes electricity
  29. 252
  30. 0.2
  31. 240
  32. 1
  33. switch off empty rooms
  34. 1
  35. 720
  36. leave the TV on standby
  37. 136
  38. saves electricity
  39. True
  40. True

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