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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 219 · 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.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  2. 2.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  3. 3.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  4. 4.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  5. 5.🧾 A family uses 200 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  6. 6.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 watt (d) 1 volt
  7. 7.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  8. 8.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  9. 9.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  10. 10.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
  11. 11.🧾 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
  12. 12.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  13. 13.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) set the AC to 24 °C (d) iron one shirt at a time
  14. 14.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  15. 15.🧾 A 1500 W appliance runs for 2 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 1 hour. How many watt-hours (Wh) are saved?
  17. 17.🔍 Which is the odd one out? (a) leave fridge door open (b) use LED lamps (c) run fans in empty rooms (d) iron one shirt at a time
  18. 18.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) iron one shirt at a time (d) use daylight to read
  19. 19.True or false: to use daylight to read saves electricity. (a) False (b) True
  20. 20.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) unplug idle chargers (d) leave fridge door open
  21. 21.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  22. 22.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  23. 23.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  24. 24.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  25. 25.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  26. 26.Which of these wastes electricity? (a) set the AC to 24 °C (b) use daylight to read (c) unplug idle chargers (d) use old filament bulbs
  27. 27.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
  28. 28.🔍 Which is the odd one out? (a) switch off empty rooms (b) leave the TV on standby (c) unplug idle chargers (d) close the fridge quickly
  29. 29.🧾 A family uses 120 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  30. 30.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  31. 31.Which of these wastes electricity? (a) close the fridge quickly (b) run fans in empty rooms (c) set the AC to 24 °C (d) switch off empty rooms
  32. 32.🔍 Which is the odd one out? (a) switch off empty rooms (b) unplug idle chargers (c) use old filament bulbs (d) set the AC to 24 °C
  33. 33.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) close the fridge quickly (d) use old filament bulbs
  34. 34.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  35. 35.True or false: to switch off empty rooms saves electricity. (a) False (b) True
  36. 36.🧾 A family uses 150 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  37. 37.Which of these saves electricity? (a) use old filament bulbs (b) use LED lamps (c) run fans in empty rooms (d) leave the TV on standby
  38. 38.True or false: to leave fridge door open saves electricity. (a) True (b) False
  39. 39.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  40. 40.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False

Answer key

  1. saves electricity
  2. 136
  3. 504
  4. 0.3
  5. 1800
  6. 1 kilowatt-hour (kWh)
  7. saves electricity
  8. 0.2
  9. wastes electricity
  10. False
  11. an LED lamp
  12. False
  13. set the AC to 24 °C
  14. wastes electricity
  15. 3
  16. 34
  17. use LED lamps
  18. iron one shirt at a time
  19. True
  20. unplug idle chargers
  21. 510
  22. False
  23. 0.25
  24. wastes electricity
  25. 0.5
  26. use old filament bulbs
  27. wastes electricity
  28. leave the TV on standby
  29. 480
  30. 0.2
  31. run fans in empty rooms
  32. use old filament bulbs
  33. close the fridge quickly
  34. 1.5
  35. True
  36. 750
  37. use LED lamps
  38. False
  39. saves electricity
  40. True

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