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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 108 · 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 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  2. 2.True or false: to leave fridge door open saves electricity. (a) True (b) False
  3. 3.🧾 A family uses 160 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  4. 4.True or false: to use LED lamps saves electricity. (a) True (b) False
  5. 5.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
  6. 6.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  7. 7.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  8. 8.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  9. 9.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) iron one shirt at a time (d) switch off empty rooms
  10. 10.Which of these wastes electricity? (a) set the AC to 24 °C (b) run fans in empty rooms (c) unplug idle chargers (d) use LED lamps
  11. 11.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use LED lamps (c) use daylight to read (d) iron one shirt at a time
  12. 12.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  13. 13.Which of these saves electricity? (a) set the AC to 24 °C (b) run fans in empty rooms (c) leave the TV on standby (d) use old filament bulbs
  14. 14.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  15. 15.🔍 Which is the odd one out? (a) unplug idle chargers (b) switch off empty rooms (c) run fans in empty rooms (d) close the fridge quickly
  16. 16.Which of these wastes electricity? (a) set the AC to 24 °C (b) switch off empty rooms (c) leave fridge door open (d) use daylight to read
  17. 17.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  18. 18.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  19. 19.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) iron one shirt at a time (d) use LED lamps
  20. 20.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) a candle (d) an LED lamp
  21. 21.🧾 A 100 W filament bulb is swapped for a 15 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 switch off empty rooms wastes electricity. (a) True (b) False
  23. 23.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
  24. 24.Which of these wastes electricity? (a) switch off empty rooms (b) use old filament bulbs (c) use daylight to read (d) set the AC to 24 °C
  25. 25.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  26. 26.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
  27. 27.🧾 A family uses 150 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  28. 28.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  29. 29.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  30. 30.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave the TV on standby (c) use LED lamps (d) leave fridge door open
  31. 31.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) switch off empty rooms (d) set the AC to 24 °C
  32. 32.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) unplug idle chargers (d) iron one shirt at a time
  33. 33.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
  34. 34.Which of these saves electricity? (a) close the fridge quickly (b) iron one shirt at a time (c) use old filament bulbs (d) leave fridge door open
  35. 35.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  36. 36.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  37. 37.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
  38. 38.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
  39. 39.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  40. 40.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity

Answer key

  1. 306
  2. False
  3. 640
  4. True
  5. 1 kilowatt-hour (kWh)
  6. True
  7. saves electricity
  8. saves electricity
  9. switch off empty rooms
  10. run fans in empty rooms
  11. iron one shirt at a time
  12. wastes electricity
  13. set the AC to 24 °C
  14. 2
  15. run fans in empty rooms
  16. leave fridge door open
  17. 10
  18. saves electricity
  19. iron one shirt at a time
  20. an LED lamp
  21. 850
  22. False
  23. wastes electricity
  24. use old filament bulbs
  25. wastes electricity
  26. True
  27. 1200
  28. 0.3
  29. 5
  30. use LED lamps
  31. leave the TV on standby
  32. unplug idle chargers
  33. True
  34. close the fridge quickly
  35. 160
  36. 0.4
  37. False
  38. True
  39. 1.5
  40. saves electricity

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