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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 845 · 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 saves electricity? (a) run fans in empty rooms (b) set the AC to 24 °C (c) leave fridge door open (d) leave the TV on standby
  2. 2.True or false: to leave fridge door open saves electricity. (a) False (b) True
  3. 3.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  4. 4.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) close the fridge quickly (d) iron one shirt at a time
  5. 5.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 volt
  6. 6.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  7. 7.Which of these wastes electricity? (a) close the fridge quickly (b) use daylight to read (c) set the AC to 24 °C (d) run fans in empty rooms
  8. 8.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) leave fridge door open (d) use LED lamps
  9. 9.🔍 Which is the odd one out? (a) switch off empty rooms (b) iron one shirt at a time (c) use LED lamps (d) use daylight to read
  10. 10.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  11. 11.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an LED lamp (c) an oil lamp (d) a filament bulb
  12. 12.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  13. 13.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  14. 14.🧾 A family uses 100 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  15. 15.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  16. 16.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  17. 17.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  18. 18.🔍 Which is the odd one out? (a) run fans in empty rooms (b) switch off empty rooms (c) use LED lamps (d) use daylight to read
  19. 19.🧾 A family uses 70 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  20. 20.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  21. 21.Which of these wastes electricity? (a) unplug idle chargers (b) close the fridge quickly (c) use LED lamps (d) leave the TV on standby
  22. 22.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
  23. 23.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
  24. 24.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  25. 25.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  26. 26.🧾 A family uses 160 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  27. 27.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  28. 28.🧾 A family uses 190 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  29. 29.Which of these wastes electricity? (a) unplug idle chargers (b) use LED lamps (c) use daylight to read (d) leave fridge door open
  30. 30.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  31. 31.🔍 Which is the odd one out? (a) iron one shirt at a time (b) run fans in empty rooms (c) set the AC to 24 °C (d) leave fridge door open
  32. 32.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  33. 33.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  34. 34.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  35. 35.🧾 A 2000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  36. 36.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
  37. 37.🧾 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?
  38. 38.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  39. 39.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  40. 40.True or false: to use old filament bulbs saves electricity. (a) False (b) True

Answer key

  1. set the AC to 24 °C
  2. False
  3. True
  4. iron one shirt at a time
  5. 1 kilowatt-hour (kWh)
  6. 340
  7. run fans in empty rooms
  8. use LED lamps
  9. iron one shirt at a time
  10. 255
  11. an LED lamp
  12. saves electricity
  13. 160
  14. 700
  15. True
  16. wastes electricity
  17. 204
  18. run fans in empty rooms
  19. 490
  20. saves electricity
  21. leave the TV on standby
  22. wastes electricity
  23. True
  24. 567
  25. 5
  26. 800
  27. saves electricity
  28. 1330
  29. leave fridge door open
  30. 0.5
  31. set the AC to 24 °C
  32. saves electricity
  33. 1
  34. 0.5
  35. 20
  36. False
  37. 136
  38. wastes electricity
  39. 1.25
  40. False

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