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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 639 · 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.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  2. 2.True or false: to switch off empty rooms saves electricity. (a) True (b) False
  3. 3.🧾 A family uses 30 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  4. 4.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
  5. 5.🧾 A family uses 190 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  6. 6.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
  7. 7.🧾 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
  8. 8.Which of these saves electricity? (a) run fans in empty rooms (b) use LED lamps (c) leave the TV on standby (d) iron one shirt at a time
  9. 9.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  10. 10.Which of these wastes electricity? (a) use old filament bulbs (b) close the fridge quickly (c) use daylight to read (d) use LED lamps
  11. 11.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  12. 12.Which of these saves electricity? (a) leave the TV on standby (b) use daylight to read (c) run fans in empty rooms (d) leave fridge door open
  13. 13.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) close the fridge quickly (d) use old filament bulbs
  14. 14.🧾 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?
  15. 15.🧾 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?
  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 9 hours. How many watt-hours (Wh) are saved?
  17. 17.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  18. 18.🧾 A family uses 170 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  19. 19.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) unplug idle chargers (d) leave the TV on standby
  20. 20.Which of these wastes electricity? (a) use daylight to read (b) leave the TV on standby (c) use LED lamps (d) switch off empty rooms
  21. 21.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  22. 22.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  23. 23.Which of these wastes electricity? (a) leave fridge door open (b) switch off empty rooms (c) unplug idle chargers (d) use daylight to read
  24. 24.True or false: to use LED lamps wastes electricity. (a) True (b) False
  25. 25.Which of these saves electricity? (a) use old filament bulbs (b) set the AC to 24 °C (c) leave the TV on standby (d) iron one shirt at a time
  26. 26.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
  27. 27.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  28. 28.🔍 Which is the odd one out? (a) use daylight to read (b) leave fridge door open (c) use old filament bulbs (d) leave the TV on standby
  29. 29.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  30. 30.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  31. 31.🔍 Which is the odd one out? (a) close the fridge quickly (b) run fans in empty rooms (c) set the AC to 24 °C (d) use daylight to read
  32. 32.True or false: to close the fridge quickly saves electricity. (a) True (b) False
  33. 33.True or false: to leave fridge door open wastes electricity. (a) True (b) False
  34. 34.True or false: to leave fridge door open saves electricity. (a) True (b) False
  35. 35.🧾 A family uses 60 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  36. 36.🧾 A family uses 100 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  37. 37.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  38. 38.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  39. 39.🧾 A family uses 130 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  40. 40.True or false: to use daylight to read wastes electricity. (a) True (b) False

Answer key

  1. True
  2. True
  3. 210
  4. False
  5. 1140
  6. 1 kilowatt-hour (kWh)
  7. an LED lamp
  8. use LED lamps
  9. 126
  10. use old filament bulbs
  11. saves electricity
  12. use daylight to read
  13. close the fridge quickly
  14. 34
  15. 153
  16. 306
  17. wastes electricity
  18. 680
  19. unplug idle chargers
  20. leave the TV on standby
  21. 8
  22. 0.5
  23. leave fridge door open
  24. False
  25. set the AC to 24 °C
  26. True
  27. 4
  28. use daylight to read
  29. 6
  30. 459
  31. run fans in empty rooms
  32. True
  33. True
  34. False
  35. 240
  36. 800
  37. 0.5
  38. 85
  39. 650
  40. False

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