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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 726 · 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 of these saves electricity? (a) close the fridge quickly (b) run fans in empty rooms (c) leave the TV on standby (d) use old filament bulbs
  2. 2.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
  3. 3.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a candle (c) a filament bulb (d) an LED lamp
  4. 4.🧾 A family uses 120 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  5. 5.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  6. 6.🧾 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?
  7. 7.🔍 Which is the odd one out? (a) use daylight to read (b) iron one shirt at a time (c) leave the TV on standby (d) use old filament bulbs
  8. 8.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  9. 9.True or false: to unplug idle chargers saves electricity. (a) False (b) True
  10. 10.🔍 Which is the odd one out? (a) use daylight to read (b) switch off empty rooms (c) unplug idle chargers (d) run fans in empty rooms
  11. 11.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  12. 12.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  13. 13.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) set the AC to 24 °C (d) leave fridge door open
  14. 14.🔍 Which is the odd one out? (a) leave the TV on standby (b) unplug idle chargers (c) iron one shirt at a time (d) run fans in empty rooms
  15. 15.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  16. 16.Which of these saves electricity? (a) iron one shirt at a time (b) leave fridge door open (c) run fans in empty rooms (d) use daylight to read
  17. 17.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  18. 18.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
  19. 19.True or false: to switch off empty rooms saves electricity. (a) False (b) True
  20. 20.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  21. 21.Which of these saves electricity? (a) iron one shirt at a time (b) leave fridge door open (c) use LED lamps (d) leave the TV on standby
  22. 22.Which of these wastes electricity? (a) unplug idle chargers (b) close the fridge quickly (c) set the AC to 24 °C (d) run fans in empty rooms
  23. 23.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  24. 24.True or false: to run fans in empty rooms wastes electricity. (a) True (b) False
  25. 25.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
  26. 26.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  27. 27.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
  28. 28.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
  29. 29.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  30. 30.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
  31. 31.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  32. 32.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  33. 33.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) set the AC to 24 °C (d) leave the TV on standby
  34. 34.True or false: to close the fridge quickly saves electricity. (a) False (b) True
  35. 35.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
  36. 36.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  37. 37.Which of these saves electricity? (a) switch off empty rooms (b) iron one shirt at a time (c) run fans in empty rooms (d) leave the TV on standby
  38. 38.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  39. 39.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
  40. 40.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =

Answer key

  1. close the fridge quickly
  2. 1 kilowatt-hour (kWh)
  3. an LED lamp
  4. 960
  5. 459
  6. 63
  7. use daylight to read
  8. saves electricity
  9. True
  10. run fans in empty rooms
  11. saves electricity
  12. 0.1
  13. set the AC to 24 °C
  14. unplug idle chargers
  15. 0.8
  16. use daylight to read
  17. 51
  18. saves electricity
  19. True
  20. 0.3
  21. use LED lamps
  22. run fans in empty rooms
  23. 170
  24. True
  25. True
  26. wastes electricity
  27. False
  28. False
  29. 1020
  30. True
  31. 0.5
  32. wastes electricity
  33. leave the TV on standby
  34. True
  35. wastes electricity
  36. 153
  37. switch off empty rooms
  38. 102
  39. saves electricity
  40. 3

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