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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 43 · 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 wastes electricity? (a) unplug idle chargers (b) use old filament bulbs (c) close the fridge quickly (d) switch off empty rooms
  2. 2.🔍 Which is the odd one out? (a) unplug idle chargers (b) set the AC to 24 °C (c) switch off empty rooms (d) run fans in empty rooms
  3. 3.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  4. 4.🔍 Which is the odd one out? (a) leave fridge door open (b) close the fridge quickly (c) leave the TV on standby (d) use old filament bulbs
  5. 5.Which of these wastes electricity? (a) leave the TV on standby (b) switch off empty rooms (c) use daylight to read (d) use LED lamps
  6. 6.Which of these saves electricity? (a) iron one shirt at a time (b) use daylight to read (c) leave fridge door open (d) run fans in empty rooms
  7. 7.Which of these wastes electricity? (a) switch off empty rooms (b) close the fridge quickly (c) set the AC to 24 °C (d) iron one shirt at a time
  8. 8.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  9. 9.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 watt
  10. 10.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  11. 11.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  12. 12.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  13. 13.🧾 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
  14. 14.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  15. 15.True or false: to use daylight to read wastes electricity. (a) True (b) False
  16. 16.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  17. 17.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
  18. 18.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) use LED lamps (d) leave fridge door open
  19. 19.True or false: to switch off empty rooms saves electricity. (a) True (b) False
  20. 20.🧾 A family uses 200 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  21. 21.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  22. 22.🧾 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?
  23. 23.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  24. 24.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) leave the TV on standby (d) leave fridge door open
  25. 25.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  26. 26.🧾 A family uses 130 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  27. 27.🧾 A family uses 60 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  28. 28.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) close the fridge quickly (d) iron one shirt at a time
  29. 29.🧾 A family uses 50 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  30. 30.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
  31. 31.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  32. 32.Which of these saves electricity? (a) iron one shirt at a time (b) switch off empty rooms (c) run fans in empty rooms (d) leave fridge door open
  33. 33.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  34. 34.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  35. 35.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) use old filament bulbs (d) switch off empty rooms
  36. 36.🔍 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) set the AC to 24 °C
  37. 37.🧾 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?
  38. 38.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  39. 39.🧾 A 1500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  40. 40.🔍 Which is the odd one out? (a) close the fridge quickly (b) set the AC to 24 °C (c) iron one shirt at a time (d) use LED lamps

Answer key

  1. use old filament bulbs
  2. run fans in empty rooms
  3. 8
  4. close the fridge quickly
  5. leave the TV on standby
  6. use daylight to read
  7. iron one shirt at a time
  8. True
  9. 1 kilowatt-hour (kWh)
  10. 315
  11. 0.25
  12. saves electricity
  13. an LED lamp
  14. saves electricity
  15. False
  16. saves electricity
  17. True
  18. use LED lamps
  19. True
  20. 1600
  21. True
  22. 102
  23. True
  24. switch off empty rooms
  25. 680
  26. 910
  27. 360
  28. close the fridge quickly
  29. 200
  30. wastes electricity
  31. False
  32. switch off empty rooms
  33. 0.8
  34. 2.5
  35. use old filament bulbs
  36. set the AC to 24 °C
  37. 51
  38. 1.6
  39. 7.5
  40. iron one shirt at a time

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