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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 49 · 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) use old filament bulbs (b) use LED lamps (c) run fans in empty rooms (d) leave fridge door open
  2. 2.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  3. 3.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
  4. 4.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
  5. 5.🔍 Which is the odd one out? (a) unplug idle chargers (b) use LED lamps (c) iron one shirt at a time (d) use daylight to read
  6. 6.🔍 Which is the odd one out? (a) use LED lamps (b) use old filament bulbs (c) set the AC to 24 °C (d) unplug idle chargers
  7. 7.Which of these wastes electricity? (a) use LED lamps (b) run fans in empty rooms (c) switch off empty rooms (d) close the fridge quickly
  8. 8.🔍 Which is the odd one out? (a) use daylight to read (b) unplug idle chargers (c) use LED lamps (d) leave the TV on standby
  9. 9.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) a candle (d) an oil lamp
  10. 10.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use LED lamps (c) leave the TV on standby (d) use old filament bulbs
  11. 11.🧾 A family uses 110 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  12. 12.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  13. 13.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
  14. 14.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  15. 15.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  16. 16.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  17. 17.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  18. 18.🧾 A family uses 70 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  19. 19.True or false: to leave the TV on standby saves electricity. (a) False (b) True
  20. 20.🧾 A family uses 30 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  21. 21.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) leave fridge door open (c) iron one shirt at a time (d) run fans in empty rooms
  22. 22.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  23. 23.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
  24. 24.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  25. 25.True or false: to use LED lamps saves electricity. (a) True (b) False
  26. 26.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
  27. 27.🧾 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?
  28. 28.True or false: to use LED lamps wastes electricity. (a) True (b) False
  29. 29.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
  30. 30.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  31. 31.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
  32. 32.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) close the fridge quickly (d) iron one shirt at a time
  33. 33.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  34. 34.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  35. 35.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  36. 36.🧾 A family uses 190 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  37. 37.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
  38. 38.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
  39. 39.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
  40. 40.Which of these wastes electricity? (a) iron one shirt at a time (b) use LED lamps (c) close the fridge quickly (d) set the AC to 24 °C

Answer key

  1. use LED lamps
  2. False
  3. wastes electricity
  4. 1 kilowatt-hour (kWh)
  5. iron one shirt at a time
  6. use old filament bulbs
  7. run fans in empty rooms
  8. leave the TV on standby
  9. an LED lamp
  10. use LED lamps
  11. 770
  12. 680
  13. True
  14. 504
  15. 2
  16. 12
  17. 2
  18. 490
  19. False
  20. 210
  21. set the AC to 24 °C
  22. 0.5
  23. 567
  24. wastes electricity
  25. True
  26. wastes electricity
  27. 170
  28. False
  29. wastes electricity
  30. saves electricity
  31. False
  32. close the fridge quickly
  33. 5
  34. 3
  35. 189
  36. 1330
  37. False
  38. True
  39. 255
  40. iron one shirt at a time

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