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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 563 · 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 10 hours. How many watt-hours (Wh) are saved?
  2. 2.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  3. 3.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 watt (d) 1 volt
  4. 4.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
  5. 5.🧾 A family uses 120 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  6. 6.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  7. 7.True or false: to switch off empty rooms saves electricity. (a) False (b) True
  8. 8.True or false: to use daylight to read wastes electricity. (a) False (b) True
  9. 9.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  10. 10.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  11. 11.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  12. 12.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  13. 13.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  14. 14.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  15. 15.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  16. 16.True or false: to use LED lamps wastes electricity. (a) False (b) True
  17. 17.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  18. 18.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) unplug idle chargers (d) leave the TV on standby
  19. 19.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  20. 20.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) close the fridge quickly (d) leave fridge door open
  21. 21.🔍 Which is the odd one out? (a) leave fridge door open (b) leave the TV on standby (c) run fans in empty rooms (d) use LED lamps
  22. 22.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  23. 23.🔍 Which is the odd one out? (a) leave fridge door open (b) use old filament bulbs (c) run fans in empty rooms (d) switch off empty rooms
  24. 24.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) a candle (d) an LED lamp
  25. 25.Which of these saves electricity? (a) use old filament bulbs (b) unplug idle chargers (c) leave fridge door open (d) run fans in empty rooms
  26. 26.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  27. 27.True or false: to use daylight to read saves electricity. (a) False (b) True
  28. 28.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) leave fridge door open (c) unplug idle chargers (d) close the fridge quickly
  29. 29.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  30. 30.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  31. 31.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
  32. 32.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) set the AC to 24 °C (d) iron one shirt at a time
  33. 33.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False
  34. 34.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  35. 35.🔍 Which is the odd one out? (a) unplug idle chargers (b) switch off empty rooms (c) set the AC to 24 °C (d) run fans in empty rooms
  36. 36.🧾 A family uses 110 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  37. 37.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
  38. 38.🔍 Which is the odd one out? (a) iron one shirt at a time (b) close the fridge quickly (c) switch off empty rooms (d) unplug idle chargers
  39. 39.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  40. 40.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =

Answer key

  1. 340
  2. saves electricity
  3. 1 kilowatt-hour (kWh)
  4. wastes electricity
  5. 600
  6. True
  7. True
  8. False
  9. saves electricity
  10. 0.3
  11. 68
  12. 5
  13. saves electricity
  14. saves electricity
  15. saves electricity
  16. False
  17. 2
  18. unplug idle chargers
  19. 189
  20. close the fridge quickly
  21. use LED lamps
  22. False
  23. switch off empty rooms
  24. an LED lamp
  25. unplug idle chargers
  26. True
  27. True
  28. leave fridge door open
  29. 6
  30. 10
  31. False
  32. set the AC to 24 °C
  33. True
  34. 408
  35. run fans in empty rooms
  36. 440
  37. wastes electricity
  38. iron one shirt at a time
  39. True
  40. 0.4

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