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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 382 · 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) iron one shirt at a time (b) leave the TV on standby (c) use old filament bulbs (d) set the AC to 24 °C
  2. 2.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) use daylight to read (d) use old filament bulbs
  3. 3.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) close the fridge quickly (d) leave fridge door open
  4. 4.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) use old filament bulbs (d) use LED lamps
  5. 5.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 ampere (d) 1 volt
  6. 6.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  7. 7.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) a filament bulb (d) an oil lamp
  8. 8.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
  9. 9.🧾 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?
  10. 10.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
  11. 11.🔍 Which is the odd one out? (a) switch off empty rooms (b) use old filament bulbs (c) set the AC to 24 °C (d) use LED lamps
  12. 12.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  13. 13.🧾 A family uses 160 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  14. 14.True or false: to use LED lamps wastes electricity. (a) True (b) False
  15. 15.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  16. 16.🔍 Which is the odd one out? (a) leave fridge door open (b) switch off empty rooms (c) iron one shirt at a time (d) run fans in empty rooms
  17. 17.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  18. 18.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  19. 19.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  20. 20.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
  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 leave the TV on standby? (a) wastes electricity (b) saves electricity
  23. 23.🧾 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?
  24. 24.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  25. 25.Which of these saves electricity? (a) leave fridge door open (b) use daylight to read (c) run fans in empty rooms (d) leave the TV on standby
  26. 26.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) leave fridge door open (d) use LED lamps
  27. 27.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  29. 29.🧾 A 2000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  30. 30.🧾 A family uses 50 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  31. 31.🧾 A family uses 110 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  32. 32.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  33. 33.🔍 Which is the odd one out? (a) leave the TV on standby (b) unplug idle chargers (c) set the AC to 24 °C (d) close the fridge quickly
  34. 34.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
  35. 35.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
  36. 36.🔍 Which is the odd one out? (a) close the fridge quickly (b) run fans in empty rooms (c) use LED lamps (d) use daylight to read
  37. 37.Which of these wastes electricity? (a) switch off empty rooms (b) use LED lamps (c) set the AC to 24 °C (d) iron one shirt at a time
  38. 38.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  39. 39.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  40. 40.True or false: to leave the TV on standby saves electricity. (a) True (b) False

Answer key

  1. set the AC to 24 °C
  2. use daylight to read
  3. close the fridge quickly
  4. use LED lamps
  5. 1 kilowatt-hour (kWh)
  6. 0.4
  7. an LED lamp
  8. 85
  9. 51
  10. 340
  11. use old filament bulbs
  12. wastes electricity
  13. 1440
  14. False
  15. 238
  16. switch off empty rooms
  17. 2
  18. 0.6
  19. saves electricity
  20. False
  21. saves electricity
  22. wastes electricity
  23. 408
  24. 8
  25. use daylight to read
  26. use LED lamps
  27. 10
  28. 2.5
  29. 12
  30. 450
  31. 990
  32. saves electricity
  33. leave the TV on standby
  34. saves electricity
  35. saves electricity
  36. run fans in empty rooms
  37. iron one shirt at a time
  38. False
  39. 0.2
  40. False

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