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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 561 · 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 close the fridge quickly? (a) wastes electricity (b) saves electricity
  2. 2.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  3. 3.🔍 Which is the odd one out? (a) leave fridge door open (b) use daylight to read (c) iron one shirt at a time (d) use old filament bulbs
  4. 4.🔍 Which is the odd one out? (a) switch off empty rooms (b) leave the TV on standby (c) iron one shirt at a time (d) run fans in empty rooms
  5. 5.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) use LED lamps (d) iron one shirt at a time
  6. 6.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  7. 7.🧾 A 500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  8. 8.🧾 A 1000 W appliance runs for 10 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.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  11. 11.🧾 A family uses 140 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  12. 12.Which of these saves electricity? (a) leave fridge door open (b) run fans in empty rooms (c) use old filament bulbs (d) use daylight to read
  13. 13.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
  14. 14.Which of these wastes electricity? (a) set the AC to 24 °C (b) leave fridge door open (c) unplug idle chargers (d) switch off empty rooms
  15. 15.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) use LED lamps (d) leave the TV on standby
  16. 16.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  17. 17.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  18. 18.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
  19. 19.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) unplug idle chargers (d) leave the TV on standby
  20. 20.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  21. 21.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  22. 22.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  23. 23.🧾 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?
  24. 24.🔍 Which is the odd one out? (a) unplug idle chargers (b) iron one shirt at a time (c) leave the TV on standby (d) use old filament bulbs
  25. 25.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  26. 26.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  27. 27.Which of these saves electricity? (a) close the fridge quickly (b) leave the TV on standby (c) use old filament bulbs (d) iron one shirt at a time
  28. 28.🧾 A family uses 20 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  29. 29.🔍 Which is the odd one out? (a) close the fridge quickly (b) use old filament bulbs (c) use daylight to read (d) unplug idle chargers
  30. 30.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
  31. 31.🧾 A family uses 40 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  32. 32.True or false: to use LED lamps saves electricity. (a) True (b) False
  33. 33.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) set the AC to 24 °C (d) leave fridge door open
  34. 34.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) iron one shirt at a time (d) use daylight to read
  35. 35.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  36. 36.🔍 Which is the odd one out? (a) leave fridge door open (b) switch off empty rooms (c) close the fridge quickly (d) set the AC to 24 °C
  37. 37.True or false: to use old filament bulbs saves electricity. (a) False (b) True
  38. 38.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  39. 39.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  40. 40.True or false: to unplug idle chargers saves electricity. (a) True (b) False

Answer key

  1. saves electricity
  2. 0.25
  3. use daylight to read
  4. switch off empty rooms
  5. use LED lamps
  6. 2
  7. 4
  8. 10
  9. saves electricity
  10. 0.4
  11. 560
  12. use daylight to read
  13. 1 kilowatt-hour (kWh)
  14. leave fridge door open
  15. use LED lamps
  16. 63
  17. False
  18. True
  19. unplug idle chargers
  20. 16
  21. False
  22. 170
  23. 126
  24. unplug idle chargers
  25. True
  26. 15
  27. close the fridge quickly
  28. 120
  29. use old filament bulbs
  30. an LED lamp
  31. 280
  32. True
  33. set the AC to 24 °C
  34. iron one shirt at a time
  35. wastes electricity
  36. leave fridge door open
  37. False
  38. wastes electricity
  39. saves electricity
  40. True

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