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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 444 · 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 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  2. 2.🔍 Which is the odd one out? (a) switch off empty rooms (b) use old filament bulbs (c) leave the TV on standby (d) iron one shirt at a time
  3. 3.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
  4. 4.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  5. 5.True or false: to use old filament bulbs saves electricity. (a) True (b) False
  6. 6.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  7. 7.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
  8. 8.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  9. 9.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  10. 10.🧾 A family uses 60 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  11. 11.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 watt
  12. 12.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  13. 13.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  14. 14.Which of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) use old filament bulbs (d) leave fridge door open
  15. 15.🔍 Which is the odd one out? (a) use LED lamps (b) unplug idle chargers (c) iron one shirt at a time (d) switch off empty rooms
  16. 16.🔍 Which is the odd one out? (a) switch off empty rooms (b) set the AC to 24 °C (c) unplug idle chargers (d) leave the TV on standby
  17. 17.True or false: to use daylight to read wastes electricity. (a) True (b) False
  18. 18.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) iron one shirt at a time (d) unplug idle chargers
  19. 19.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
  20. 20.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  21. 21.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  22. 22.Which of these wastes electricity? (a) unplug idle chargers (b) use old filament bulbs (c) use daylight to read (d) set the AC to 24 °C
  23. 23.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) unplug idle chargers (d) leave the TV on standby
  24. 24.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  25. 25.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  26. 26.🔍 Which is the odd one out? (a) iron one shirt at a time (b) set the AC to 24 °C (c) leave fridge door open (d) leave the TV on standby
  27. 27.🔍 Which is the odd one out? (a) use old filament bulbs (b) use daylight to read (c) unplug idle chargers (d) close the fridge quickly
  28. 28.Which of these saves electricity? (a) switch off empty rooms (b) leave fridge door open (c) leave the TV on standby (d) iron one shirt at a time
  29. 29.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  30. 30.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  31. 31.🔍 Which is the odd one out? (a) use old filament bulbs (b) use LED lamps (c) run fans in empty rooms (d) leave fridge door open
  32. 32.True or false: to use LED lamps saves electricity. (a) True (b) False
  33. 33.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  34. 34.🧾 A family uses 190 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  35. 35.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
  36. 36.🧾 A family uses 20 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  37. 37.True or false: to use LED lamps wastes electricity. (a) False (b) True
  38. 38.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  39. 39.Which of these wastes electricity? (a) set the AC to 24 °C (b) switch off empty rooms (c) close the fridge quickly (d) run fans in empty rooms
  40. 40.True or false: to set the AC to 24 °C wastes electricity. (a) False (b) True

Answer key

  1. 0.25
  2. switch off empty rooms
  3. an LED lamp
  4. saves electricity
  5. False
  6. 0.8
  7. saves electricity
  8. wastes electricity
  9. 630
  10. 360
  11. 1 kilowatt-hour (kWh)
  12. saves electricity
  13. 0.2
  14. use LED lamps
  15. iron one shirt at a time
  16. leave the TV on standby
  17. False
  18. unplug idle chargers
  19. wastes electricity
  20. 2.5
  21. False
  22. use old filament bulbs
  23. unplug idle chargers
  24. 765
  25. wastes electricity
  26. set the AC to 24 °C
  27. use old filament bulbs
  28. switch off empty rooms
  29. 5
  30. wastes electricity
  31. use LED lamps
  32. True
  33. True
  34. 760
  35. True
  36. 80
  37. False
  38. 5
  39. run fans in empty rooms
  40. False

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