← Electricity units and saving power lesson New set →

Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 448 · 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 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  2. 2.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) an oil lamp (d) a candle
  3. 3.🔍 Which is the odd one out? (a) close the fridge quickly (b) use old filament bulbs (c) iron one shirt at a time (d) leave fridge door open
  4. 4.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  5. 5.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  6. 6.True or false: to unplug idle chargers saves electricity. (a) True (b) False
  7. 7.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  8. 8.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 volt
  9. 9.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
  10. 10.🔍 Which is the odd one out? (a) leave the TV on standby (b) iron one shirt at a time (c) switch off empty rooms (d) use old filament bulbs
  11. 11.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  12. 12.Which of these saves electricity? (a) use LED lamps (b) leave the TV on standby (c) run fans in empty rooms (d) iron one shirt at a time
  13. 13.🔍 Which is the odd one out? (a) close the fridge quickly (b) switch off empty rooms (c) run fans in empty rooms (d) unplug idle chargers
  14. 14.🧾 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?
  15. 15.Which of these wastes electricity? (a) set the AC to 24 °C (b) leave the TV on standby (c) switch off empty rooms (d) unplug idle chargers
  16. 16.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
  17. 17.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  18. 18.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) use daylight to read (d) iron one shirt at a time
  19. 19.Which of these wastes electricity? (a) use old filament bulbs (b) use daylight to read (c) switch off empty rooms (d) use LED lamps
  20. 20.🔍 Which is the odd one out? (a) leave fridge door open (b) leave the TV on standby (c) use LED lamps (d) use old filament bulbs
  21. 21.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
  22. 22.True or false: to use LED lamps wastes electricity. (a) True (b) False
  23. 23.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
  24. 24.True or false: to use LED lamps saves electricity. (a) False (b) True
  25. 25.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  26. 26.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
  27. 27.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  28. 28.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  29. 29.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
  30. 30.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  31. 31.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  32. 32.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
  33. 33.🧾 A 250 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  34. 34.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
  35. 35.🧾 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?
  36. 36.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  37. 37.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) switch off empty rooms (d) close the fridge quickly
  38. 38.🧾 A family uses 110 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  39. 39.🔍 Which is the odd one out? (a) switch off empty rooms (b) iron one shirt at a time (c) set the AC to 24 °C (d) use daylight to read
  40. 40.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity

Answer key

  1. 595
  2. an LED lamp
  3. close the fridge quickly
  4. 1260
  5. saves electricity
  6. True
  7. 0.3
  8. 1 kilowatt-hour (kWh)
  9. saves electricity
  10. switch off empty rooms
  11. 0.8
  12. use LED lamps
  13. run fans in empty rooms
  14. 153
  15. leave the TV on standby
  16. True
  17. 0.4
  18. use daylight to read
  19. use old filament bulbs
  20. use LED lamps
  21. saves electricity
  22. False
  23. wastes electricity
  24. True
  25. 0.25
  26. 0.2
  27. 5
  28. 0.2
  29. 510
  30. 2
  31. 8
  32. False
  33. 1
  34. 255
  35. 102
  36. 16
  37. leave the TV on standby
  38. 440
  39. iron one shirt at a time
  40. saves electricity

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