← Electricity units and saving power lesson New set →

Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 139 · 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.

NameDateTime takenScore ___ / 40
  1. 1.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
  2. 2.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  3. 3.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  4. 4.🧾 A family uses 40 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  5. 5.🔍 Which is the odd one out? (a) switch off empty rooms (b) use daylight to read (c) use LED lamps (d) use old filament bulbs
  6. 6.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
  7. 7.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) iron one shirt at a time (d) use daylight to read
  8. 8.🔍 Which is the odd one out? (a) leave fridge door open (b) close the fridge quickly (c) switch off empty rooms (d) unplug idle chargers
  9. 9.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  10. 10.True or false: to switch off empty rooms saves electricity. (a) True (b) False
  11. 11.Which of these saves electricity? (a) switch off empty rooms (b) run fans in empty rooms (c) iron one shirt at a time (d) leave fridge door open
  12. 12.🔍 Which is the odd one out? (a) close the fridge quickly (b) iron one shirt at a time (c) leave fridge door open (d) leave the TV on standby
  13. 13.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) run fans in empty rooms (d) use daylight to read
  14. 14.🧾 A family uses 20 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  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 1 hour. How many watt-hours (Wh) are saved?
  16. 16.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 volt (d) 1 watt
  17. 17.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  18. 18.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
  19. 19.🧾 A family uses 30 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  20. 20.🧾 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
  21. 21.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
  22. 22.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
  23. 23.🧾 A family uses 30 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  24. 24.🧾 A family uses 190 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
  25. 25.🧾 A family uses 90 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  26. 26.True or false: to leave fridge door open saves electricity. (a) True (b) False
  27. 27.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  29. 29.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  30. 30.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  31. 31.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  32. 32.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) switch off empty rooms (c) iron one shirt at a time (d) use LED lamps
  33. 33.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  34. 34.True or false: to use LED lamps saves electricity. (a) False (b) True
  35. 35.Which of these wastes electricity? (a) leave the TV on standby (b) switch off empty rooms (c) use daylight to read (d) set the AC to 24 °C
  36. 36.🧾 A family uses 100 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  37. 37.Which of these saves electricity? (a) use LED lamps (b) run fans in empty rooms (c) iron one shirt at a time (d) leave fridge door open
  38. 38.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
  39. 39.🧾 A family uses 180 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  40. 40.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) run fans in empty rooms (d) use daylight to read

Answer key

  1. 126
  2. 8
  3. 0.5
  4. 320
  5. use old filament bulbs
  6. saves electricity
  7. use daylight to read
  8. leave fridge door open
  9. wastes electricity
  10. True
  11. switch off empty rooms
  12. close the fridge quickly
  13. use daylight to read
  14. 100
  15. 34
  16. 1 kilowatt-hour (kWh)
  17. wastes electricity
  18. 272
  19. 120
  20. an LED lamp
  21. True
  22. wastes electricity
  23. 270
  24. 1710
  25. 360
  26. False
  27. 0.5
  28. 0.3
  29. 1
  30. 0.5
  31. 0.1
  32. iron one shirt at a time
  33. 510
  34. True
  35. leave the TV on standby
  36. 600
  37. use LED lamps
  38. 850
  39. 1440
  40. run fans in empty rooms

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids