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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 799 · 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 lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) a candle (d) an LED lamp
  2. 2.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  3. 3.Which of these wastes electricity? (a) use daylight to read (b) switch off empty rooms (c) leave fridge door open (d) use LED lamps
  4. 4.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) run fans in empty rooms (c) iron one shirt at a time (d) leave fridge door open
  5. 5.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  6. 6.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
  7. 7.🧾 A 250 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  8. 8.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) use daylight to read (d) leave the TV on standby
  9. 9.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
  10. 10.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  11. 11.🔍 Which is the odd one out? (a) leave the TV on standby (b) close the fridge quickly (c) run fans in empty rooms (d) use old filament bulbs
  12. 12.🧾 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?
  13. 13.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
  14. 14.Which of these saves electricity? (a) use LED lamps (b) use old filament bulbs (c) leave fridge door open (d) leave the TV on standby
  15. 15.🧾 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?
  16. 16.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  17. 17.True or false: to leave fridge door open saves electricity. (a) False (b) True
  18. 18.Which of these saves electricity? (a) set the AC to 24 °C (b) leave the TV on standby (c) leave fridge door open (d) iron one shirt at a time
  19. 19.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  20. 20.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
  21. 21.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  22. 22.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  23. 23.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  24. 24.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  25. 25.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  26. 26.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  27. 27.Which of these wastes electricity? (a) leave the TV on standby (b) use LED lamps (c) unplug idle chargers (d) use daylight to read
  28. 28.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  29. 29.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  30. 30.Which of these saves electricity? (a) iron one shirt at a time (b) leave fridge door open (c) leave the TV on standby (d) switch off empty rooms
  31. 31.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  32. 32.🧾 A family uses 80 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  33. 33.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
  34. 34.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
  35. 35.🧾 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?
  36. 36.Which of these wastes electricity? (a) run fans in empty rooms (b) use daylight to read (c) switch off empty rooms (d) use LED lamps
  37. 37.🔍 Which is the odd one out? (a) use LED lamps (b) run fans in empty rooms (c) use old filament bulbs (d) leave fridge door open
  38. 38.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  39. 39.🔍 Which is the odd one out? (a) use LED lamps (b) iron one shirt at a time (c) switch off empty rooms (d) unplug idle chargers
  40. 40.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity

Answer key

  1. an LED lamp
  2. True
  3. leave fridge door open
  4. set the AC to 24 °C
  5. False
  6. False
  7. 1
  8. leave the TV on standby
  9. 1 kilowatt-hour (kWh)
  10. 2.5
  11. close the fridge quickly
  12. 63
  13. True
  14. use LED lamps
  15. 126
  16. 4
  17. False
  18. set the AC to 24 °C
  19. 6
  20. saves electricity
  21. 720
  22. 0.8
  23. wastes electricity
  24. True
  25. 0.4
  26. 0.8
  27. leave the TV on standby
  28. 0.25
  29. saves electricity
  30. switch off empty rooms
  31. 0.3
  32. 480
  33. True
  34. True
  35. 34
  36. run fans in empty rooms
  37. use LED lamps
  38. 630
  39. iron one shirt at a time
  40. wastes electricity

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