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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 811 · 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) unplug idle chargers (c) leave the TV on standby (d) use old filament bulbs
  2. 2.🧾 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?
  3. 3.🧾 A family uses 80 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  4. 4.Which of these wastes electricity? (a) unplug idle chargers (b) close the fridge quickly (c) use LED lamps (d) iron one shirt at a time
  5. 5.Which of these wastes electricity? (a) set the AC to 24 °C (b) switch off empty rooms (c) leave the TV on standby (d) unplug idle chargers
  6. 6.🧾 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?
  7. 7.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  8. 8.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  9. 9.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
  10. 10.True or false: to use LED lamps saves electricity. (a) False (b) True
  11. 11.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  12. 12.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
  13. 13.Which of these saves electricity? (a) leave fridge door open (b) run fans in empty rooms (c) use daylight to read (d) leave the TV on standby
  14. 14.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) a candle (d) an LED lamp
  15. 15.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  16. 16.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
  17. 17.🧾 A family uses 90 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  18. 18.Which of these wastes electricity? (a) set the AC to 24 °C (b) unplug idle chargers (c) use LED lamps (d) use old filament bulbs
  19. 19.🧾 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?
  20. 20.Which of these saves electricity? (a) switch off empty rooms (b) iron one shirt at a time (c) leave the TV on standby (d) use old filament bulbs
  21. 21.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  22. 22.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  23. 23.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) close the fridge quickly (c) unplug idle chargers (d) iron one shirt at a time
  24. 24.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  25. 25.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  26. 26.True or false: to use daylight to read wastes electricity. (a) False (b) True
  27. 27.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  29. 29.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  30. 30.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  31. 31.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  32. 32.🧾 A family uses 120 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  33. 33.Which of these wastes electricity? (a) use daylight to read (b) switch off empty rooms (c) run fans in empty rooms (d) set the AC to 24 °C
  34. 34.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  35. 35.🧾 A family uses 80 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  36. 36.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  37. 37.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) leave fridge door open (d) close the fridge quickly
  38. 38.🧾 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?
  39. 39.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  40. 40.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use old filament bulbs (c) use daylight to read (d) leave the TV on standby

Answer key

  1. unplug idle chargers
  2. 441
  3. 640
  4. iron one shirt at a time
  5. leave the TV on standby
  6. 34
  7. 0.5
  8. 425
  9. saves electricity
  10. True
  11. wastes electricity
  12. 1 kilowatt-hour (kWh)
  13. use daylight to read
  14. an LED lamp
  15. 2
  16. 204
  17. 810
  18. use old filament bulbs
  19. 408
  20. switch off empty rooms
  21. False
  22. 3
  23. iron one shirt at a time
  24. 300
  25. saves electricity
  26. False
  27. 1
  28. 0.2
  29. wastes electricity
  30. True
  31. 4
  32. 1080
  33. run fans in empty rooms
  34. saves electricity
  35. 720
  36. True
  37. close the fridge quickly
  38. 126
  39. 8
  40. use daylight to read

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