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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 89 · 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) unplug idle chargers (b) switch off empty rooms (c) close the fridge quickly (d) iron one shirt at a time
  2. 2.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  3. 3.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  4. 4.🧾 A family uses 110 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  5. 5.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  6. 6.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  7. 7.🧾 A family uses 80 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  8. 8.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
  9. 9.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  10. 10.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
  11. 11.🧾 A family uses 140 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  12. 12.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  13. 13.🧾 A family uses 40 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  14. 14.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  15. 15.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) switch off empty rooms (d) run fans in empty rooms
  16. 16.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
  17. 17.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) use old filament bulbs (d) iron one shirt at a time
  18. 18.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  19. 19.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  20. 20.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  21. 21.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  22. 22.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  23. 23.Which of these wastes electricity? (a) leave the TV on standby (b) set the AC to 24 °C (c) close the fridge quickly (d) switch off empty rooms
  24. 24.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  25. 25.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  26. 26.True or false: to close the fridge quickly saves electricity. (a) True (b) False
  27. 27.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
  28. 28.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  29. 29.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) leave fridge door open (d) use daylight to read
  30. 30.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  31. 31.🧾 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?
  32. 32.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  33. 33.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  34. 34.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) set the AC to 24 °C (d) use old filament bulbs
  35. 35.🧾 A family uses 50 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  36. 36.Which of these wastes electricity? (a) use LED lamps (b) unplug idle chargers (c) iron one shirt at a time (d) switch off empty rooms
  37. 37.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  38. 38.Which of these saves electricity? (a) use LED lamps (b) use old filament bulbs (c) leave the TV on standby (d) run fans in empty rooms
  39. 39.🧾 A family uses 20 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  40. 40.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False

Answer key

  1. iron one shirt at a time
  2. True
  3. 51
  4. 660
  5. saves electricity
  6. saves electricity
  7. 320
  8. 1 kilowatt-hour (kWh)
  9. 1
  10. saves electricity
  11. 700
  12. 102
  13. 320
  14. 0.2
  15. switch off empty rooms
  16. an LED lamp
  17. set the AC to 24 °C
  18. False
  19. False
  20. 300
  21. wastes electricity
  22. saves electricity
  23. leave the TV on standby
  24. saves electricity
  25. wastes electricity
  26. True
  27. True
  28. 1
  29. use daylight to read
  30. 34
  31. 255
  32. 68
  33. 0.5
  34. use old filament bulbs
  35. 200
  36. iron one shirt at a time
  37. 1.6
  38. use LED lamps
  39. 100
  40. True

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