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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 210 · 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) unplug idle chargers (b) use old filament bulbs (c) iron one shirt at a time (d) leave the TV on standby
  2. 2.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) use old filament bulbs (d) use daylight to read
  3. 3.True or false: to use LED lamps wastes electricity. (a) True (b) False
  4. 4.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 ampere (d) 1 volt
  5. 5.🧾 A family uses 160 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  6. 6.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  7. 7.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  8. 8.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  9. 9.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  10. 10.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  11. 11.🧾 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
  12. 12.True or false: to leave fridge door open saves electricity. (a) False (b) True
  13. 13.True or false: to leave fridge door open wastes electricity. (a) True (b) False
  14. 14.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  15. 15.🧾 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?
  16. 16.🧾 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?
  17. 17.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  18. 18.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
  19. 19.True or false: to unplug idle chargers saves electricity. (a) True (b) False
  20. 20.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  21. 21.🔍 Which is the odd one out? (a) use daylight to read (b) switch off empty rooms (c) unplug idle chargers (d) leave the TV on standby
  22. 22.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  23. 23.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  24. 24.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
  25. 25.🧾 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?
  26. 26.🧾 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?
  27. 27.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  29. 29.🧾 A family uses 70 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  30. 30.🔍 Which is the odd one out? (a) use LED lamps (b) use daylight to read (c) iron one shirt at a time (d) switch off empty rooms
  31. 31.🧾 A family uses 150 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  32. 32.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  33. 33.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  34. 34.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  35. 35.🧾 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?
  36. 36.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  37. 37.🧾 A 50 W appliance runs for 8 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.Which of these wastes electricity? (a) leave the TV on standby (b) set the AC to 24 °C (c) use LED lamps (d) use daylight to read
  40. 40.True or false: to use daylight to read saves electricity. (a) True (b) False

Answer key

  1. unplug idle chargers
  2. use daylight to read
  3. False
  4. 1 kilowatt-hour (kWh)
  5. 1280
  6. saves electricity
  7. False
  8. 0.1
  9. saves electricity
  10. wastes electricity
  11. an LED lamp
  12. False
  13. True
  14. saves electricity
  15. 850
  16. 153
  17. wastes electricity
  18. wastes electricity
  19. True
  20. wastes electricity
  21. leave the TV on standby
  22. 1.25
  23. saves electricity
  24. saves electricity
  25. 504
  26. 126
  27. 1.5
  28. 0.8
  29. 280
  30. iron one shirt at a time
  31. 1050
  32. True
  33. wastes electricity
  34. 238
  35. 255
  36. True
  37. 0.4
  38. 85
  39. leave the TV on standby
  40. True

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