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Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 216 · 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.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
  2. 2.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 volt
  3. 3.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) leave the TV on standby (d) close the fridge quickly
  4. 4.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
  5. 5.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  6. 6.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  7. 7.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
  8. 8.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
  9. 9.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) switch off empty rooms (d) run fans in empty rooms
  10. 10.Which of these wastes electricity? (a) close the fridge quickly (b) set the AC to 24 °C (c) use LED lamps (d) run fans in empty rooms
  11. 11.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  12. 12.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
  13. 13.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) an oil lamp (d) a filament bulb
  14. 14.🔍 Which is the odd one out? (a) unplug idle chargers (b) use LED lamps (c) close the fridge quickly (d) run fans in empty rooms
  15. 15.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) run fans in empty rooms (d) close the fridge quickly
  16. 16.🧾 A family uses 60 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  17. 17.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
  18. 18.🧾 A family uses 120 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
  19. 19.🧾 A family uses 190 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
  20. 20.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
  21. 21.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
  22. 22.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  23. 23.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
  24. 24.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
  25. 25.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
  26. 26.🧾 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?
  27. 27.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
  28. 28.True or false: to close the fridge quickly saves electricity. (a) False (b) True
  29. 29.🧾 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?
  30. 30.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
  31. 31.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
  32. 32.Which of these wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) iron one shirt at a time (d) use LED lamps
  33. 33.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
  34. 34.🧾 A family uses 130 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
  35. 35.Which of these wastes electricity? (a) use LED lamps (b) leave the TV on standby (c) close the fridge quickly (d) switch off empty rooms
  36. 36.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
  37. 37.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
  38. 38.Which of these saves electricity? (a) leave fridge door open (b) run fans in empty rooms (c) use daylight to read (d) use old filament bulbs
  39. 39.🧾 A family uses 180 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
  40. 40.🧾 A family uses 90 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?

Answer key

  1. wastes electricity
  2. 1 kilowatt-hour (kWh)
  3. leave the TV on standby
  4. False
  5. 2
  6. 0.6
  7. 160
  8. saves electricity
  9. switch off empty rooms
  10. run fans in empty rooms
  11. 2.5
  12. 1.25
  13. an LED lamp
  14. run fans in empty rooms
  15. close the fridge quickly
  16. 480
  17. 0.3
  18. 960
  19. 1330
  20. 0.2
  21. saves electricity
  22. 1.6
  23. wastes electricity
  24. False
  25. False
  26. 595
  27. 16
  28. True
  29. 255
  30. False
  31. 378
  32. iron one shirt at a time
  33. True
  34. 650
  35. leave the TV on standby
  36. 15
  37. 357
  38. use daylight to read
  39. 1080
  40. 540

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