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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 515 · 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) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
  2. 2.Which of these saves electricity? (a) use LED lamps (b) leave the TV on standby (c) run fans in empty rooms (d) iron one shirt at a time
  3. 3.🔍 Which is the odd one out? (a) use daylight to read (b) close the fridge quickly (c) unplug idle chargers (d) use old filament bulbs
  4. 4.True or false: to leave fridge door open wastes electricity. (a) False (b) True
  5. 5.🧾 A family uses 50 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  6. 6.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
  7. 7.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
  8. 8.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  9. 9.Which of these wastes electricity? (a) leave the TV on standby (b) close the fridge quickly (c) unplug idle chargers (d) set the AC to 24 °C
  10. 10.🧾 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?
  11. 11.🔍 Which is the odd one out? (a) leave fridge door open (b) set the AC to 24 °C (c) switch off empty rooms (d) unplug idle chargers
  12. 12.Which of these wastes electricity? (a) use old filament bulbs (b) use daylight to read (c) use LED lamps (d) set the AC to 24 °C
  13. 13.True or false: to use LED lamps wastes electricity. (a) False (b) True
  14. 14.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  15. 15.True or false: to leave fridge door open saves electricity. (a) False (b) True
  16. 16.🔍 Which is the odd one out? (a) close the fridge quickly (b) unplug idle chargers (c) iron one shirt at a time (d) use LED lamps
  17. 17.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
  18. 18.Which of these wastes electricity? (a) leave fridge door open (b) switch off empty rooms (c) unplug idle chargers (d) close the fridge quickly
  19. 19.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  20. 20.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  21. 21.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  22. 22.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  23. 23.Which of these saves electricity? (a) set the AC to 24 °C (b) use old filament bulbs (c) leave the TV on standby (d) run fans in empty rooms
  24. 24.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  25. 25.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  26. 26.Which of these saves electricity? (a) close the fridge quickly (b) iron one shirt at a time (c) leave the TV on standby (d) run fans in empty rooms
  27. 27.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) set the AC to 24 °C (d) iron one shirt at a time
  28. 28.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
  29. 29.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  30. 30.Which of these wastes electricity? (a) iron one shirt at a time (b) set the AC to 24 °C (c) close the fridge quickly (d) switch off empty rooms
  31. 31.True or false: to use daylight to read wastes electricity. (a) False (b) True
  32. 32.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  33. 33.🔍 Which is the odd one out? (a) iron one shirt at a time (b) close the fridge quickly (c) use old filament bulbs (d) leave the TV on standby
  34. 34.🧾 A family uses 20 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  35. 35.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  36. 36.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  37. 37.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  38. 38.🧾 A family uses 20 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  39. 39.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  40. 40.🧾 A family uses 190 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?

Answer key

  1. an LED lamp
  2. use LED lamps
  3. use old filament bulbs
  4. True
  5. 250
  6. 1 kilowatt-hour (kWh)
  7. True
  8. True
  9. leave the TV on standby
  10. 306
  11. leave fridge door open
  12. use old filament bulbs
  13. False
  14. wastes electricity
  15. False
  16. iron one shirt at a time
  17. saves electricity
  18. leave fridge door open
  19. saves electricity
  20. 0.5
  21. saves electricity
  22. wastes electricity
  23. set the AC to 24 °C
  24. 8
  25. 2
  26. close the fridge quickly
  27. set the AC to 24 °C
  28. saves electricity
  29. saves electricity
  30. iron one shirt at a time
  31. False
  32. False
  33. close the fridge quickly
  34. 120
  35. 2
  36. 0.2
  37. False
  38. 140
  39. 0.2
  40. 760

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