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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 719 · 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.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  3. 3.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) leave fridge door open (d) set the AC to 24 °C
  4. 4.🧾 A family uses 160 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  5. 5.True or false: to use old filament bulbs saves electricity. (a) False (b) True
  6. 6.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  7. 7.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 volt
  8. 8.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  9. 9.🔍 Which is the odd one out? (a) use LED lamps (b) set the AC to 24 °C (c) switch off empty rooms (d) leave fridge door open
  10. 10.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  11. 11.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  12. 12.🧾 A family uses 30 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  13. 13.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  14. 14.True or false: to use LED lamps wastes electricity. (a) False (b) True
  15. 15.Which of these saves electricity? (a) leave the TV on standby (b) unplug idle chargers (c) run fans in empty rooms (d) leave fridge door open
  16. 16.True or false: to use daylight to read saves electricity. (a) False (b) True
  17. 17.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  18. 18.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
  19. 19.🧾 A family uses 90 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  20. 20.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) switch off empty rooms (d) use old filament bulbs
  21. 21.🧾 A family uses 200 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  22. 22.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) unplug idle chargers (d) run fans in empty rooms
  23. 23.🧾 A family uses 50 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  24. 24.True or false: to use daylight to read wastes electricity. (a) True (b) False
  25. 25.True or false: to set the AC to 24 °C wastes electricity. (a) False (b) True
  26. 26.🧾 A 1500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  27. 27.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  29. 29.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
  30. 30.🧾 A family uses 130 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  31. 31.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) run fans in empty rooms (d) use LED lamps
  32. 32.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  33. 33.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
  34. 34.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  35. 35.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
  36. 36.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  37. 37.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave fridge door open (c) unplug idle chargers (d) run fans in empty rooms
  38. 38.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
  39. 39.Which of these saves electricity? (a) close the fridge quickly (b) use old filament bulbs (c) iron one shirt at a time (d) run fans in empty rooms
  40. 40.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =

Answer key

  1. an LED lamp
  2. wastes electricity
  3. set the AC to 24 °C
  4. 1280
  5. False
  6. saves electricity
  7. 1 kilowatt-hour (kWh)
  8. saves electricity
  9. leave fridge door open
  10. False
  11. 3
  12. 180
  13. 102
  14. False
  15. unplug idle chargers
  16. True
  17. False
  18. saves electricity
  19. 720
  20. switch off empty rooms
  21. 800
  22. run fans in empty rooms
  23. 250
  24. False
  25. False
  26. 7.5
  27. 0.2
  28. 357
  29. wastes electricity
  30. 780
  31. use LED lamps
  32. 5
  33. saves electricity
  34. 10
  35. True
  36. saves electricity
  37. unplug idle chargers
  38. True
  39. close the fridge quickly
  40. 2

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