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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 297 · 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 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  2. 2.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) an oil lamp (d) a candle
  3. 3.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  4. 4.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  5. 5.True or false: to unplug idle chargers saves electricity. (a) True (b) False
  6. 6.🧾 A 2000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  7. 7.🧾 A family uses 40 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  8. 8.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  9. 9.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 volt
  10. 10.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  11. 11.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  12. 12.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
  13. 13.🧾 A 1500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  14. 14.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) use old filament bulbs (d) switch off empty rooms
  15. 15.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  16. 16.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) leave fridge door open (d) unplug idle chargers
  17. 17.True or false: to use old filament bulbs saves electricity. (a) True (b) False
  18. 18.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  19. 19.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  20. 20.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  21. 21.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) unplug idle chargers (d) switch off empty rooms
  22. 22.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  23. 23.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  24. 24.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  25. 25.🧾 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?
  26. 26.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  27. 27.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) leave the TV on standby (d) use LED lamps
  28. 28.Which of these wastes electricity? (a) use old filament bulbs (b) close the fridge quickly (c) set the AC to 24 °C (d) switch off empty rooms
  29. 29.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) leave the TV on standby (d) close the fridge quickly
  30. 30.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  31. 31.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
  32. 32.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  33. 33.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  34. 34.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  35. 35.🧾 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?
  36. 36.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  37. 37.True or false: to use LED lamps wastes electricity. (a) False (b) True
  38. 38.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  39. 39.Which of these wastes electricity? (a) switch off empty rooms (b) run fans in empty rooms (c) unplug idle chargers (d) use LED lamps
  40. 40.Which of these wastes electricity? (a) leave fridge door open (b) switch off empty rooms (c) use daylight to read (d) unplug idle chargers

Answer key

  1. 16
  2. an LED lamp
  3. wastes electricity
  4. saves electricity
  5. True
  6. 20
  7. 200
  8. 153
  9. 1 kilowatt-hour (kWh)
  10. 720
  11. False
  12. False
  13. 9
  14. switch off empty rooms
  15. False
  16. unplug idle chargers
  17. False
  18. 3
  19. saves electricity
  20. 12
  21. run fans in empty rooms
  22. wastes electricity
  23. 1.25
  24. saves electricity
  25. 51
  26. False
  27. leave the TV on standby
  28. use old filament bulbs
  29. close the fridge quickly
  30. 1.6
  31. True
  32. 0.25
  33. wastes electricity
  34. 340
  35. 630
  36. saves electricity
  37. False
  38. 2
  39. run fans in empty rooms
  40. leave fridge door open

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