Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 304 · 40 questions

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.

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 8 hours. How many watt-hours (Wh) are saved?
2. 2.Which of these wastes electricity? (a) switch off empty rooms (b) run fans in empty rooms (c) use daylight to read (d) set the AC to 24 °C
3. 3.Which of these wastes electricity? (a) use LED lamps (b) close the fridge quickly (c) unplug idle chargers (d) iron one shirt at a time
4. 4.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
5. 5.Which of these wastes electricity? (a) use old filament bulbs (b) use daylight to read (c) unplug idle chargers (d) switch off empty rooms
6. 6.Which of these saves electricity? (a) close the fridge quickly (b) run fans in empty rooms (c) leave the TV on standby (d) use old filament bulbs
7. 7.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
8. 8.Which of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) leave fridge door open (d) use old filament bulbs
9. 9.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) switch off empty rooms (d) use old filament bulbs
10. 10.🔍 Which is the odd one out? (a) run fans in empty rooms (b) use LED lamps (c) close the fridge quickly (d) switch off empty rooms
11. 11.🔍 Which is the odd one out? (a) leave fridge door open (b) use old filament bulbs (c) set the AC to 24 °C (d) iron one shirt at a time
12. 12.🧾 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?
13. 13.🧾 A family uses 20 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
14. 14.Which of these wastes electricity? (a) use LED lamps (b) leave fridge door open (c) set the AC to 24 °C (d) use daylight to read
15. 15.🔍 Which is the odd one out? (a) use LED lamps (b) set the AC to 24 °C (c) switch off empty rooms (d) leave the TV on standby
16. 16.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
17. 17.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) run fans in empty rooms (d) use daylight to read
18. 18.True or false: to use LED lamps saves electricity. (a) False (b) True
19. 19.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use old filament bulbs (c) leave the TV on standby (d) switch off empty rooms
20. 20.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
21. 21.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
22. 22.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
23. 23.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
24. 24.True or false: to iron one shirt at a time saves electricity. (a) False (b) True
25. 25.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
26. 26.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
27. 27.🔍 Which is the odd one out? (a) unplug idle chargers (b) switch off empty rooms (c) iron one shirt at a time (d) close the fridge quickly
28. 28.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) set the AC to 24 °C (d) use old filament bulbs
29. 29.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
30. 30.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
31. 31.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
32. 32.True or false: to switch off empty rooms saves electricity. (a) True (b) False
33. 33.🧾 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
34. 34.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) unplug idle chargers (d) iron one shirt at a time
35. 35.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
36. 36.Which of these saves electricity? (a) unplug idle chargers (b) iron one shirt at a time (c) run fans in empty rooms (d) use old filament bulbs
37. 37.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
38. 38.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
39. 39.🔍 Which is the odd one out? (a) use daylight to read (b) close the fridge quickly (c) switch off empty rooms (d) leave fridge door open
40. 40.🧾 A family uses 140 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?

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