Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 479 · 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.True or false: to switch off empty rooms saves electricity. (a) True (b) False
2. 2.Which of these wastes electricity? (a) run fans in empty rooms (b) use LED lamps (c) unplug idle chargers (d) set the AC to 24 °C
3. 3.True or false: to close the fridge quickly saves electricity. (a) True (b) False
4. 4.Which of these wastes electricity? (a) iron one shirt at a time (b) close the fridge quickly (c) use daylight to read (d) unplug idle chargers
5. 5.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
6. 6.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
7. 7.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
8. 8.🧾 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?
9. 9.True or false: to use LED lamps saves electricity. (a) True (b) False
10. 10.True or false: to leave fridge door open saves electricity. (a) False (b) True
11. 11.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
12. 12.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) use LED lamps (d) close the fridge quickly
13. 13.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
14. 14.True or false: to use LED lamps wastes electricity. (a) False (b) True
15. 15.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a filament bulb (d) a candle
16. 16.True or false: to use daylight to read wastes electricity. (a) False (b) True
17. 17.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) iron one shirt at a time (d) close the fridge quickly
18. 18.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) use daylight to read (d) leave the TV on standby
19. 19.Which of these saves electricity? (a) iron one shirt at a time (b) use old filament bulbs (c) use LED lamps (d) leave fridge door open
20. 20.🧾 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?
21. 21.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
22. 22.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) iron one shirt at a time (d) switch off empty rooms
23. 23.🔍 Which is the odd one out? (a) use daylight to read (b) run fans in empty rooms (c) iron one shirt at a time (d) leave fridge door open
24. 24.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
25. 25.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
26. 26.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
27. 27.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
28. 28.🔍 Which is the odd one out? (a) use old filament bulbs (b) switch off empty rooms (c) use daylight to read (d) set the AC to 24 °C
29. 29.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave fridge door open (c) set the AC to 24 °C (d) use old filament bulbs
30. 30.Which of these saves electricity? (a) run fans in empty rooms (b) switch off empty rooms (c) iron one shirt at a time (d) use old filament bulbs
31. 31.🔍 Which is the odd one out? (a) use LED lamps (b) use old filament bulbs (c) leave the TV on standby (d) iron one shirt at a time
32. 32.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
33. 33.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
34. 34.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
35. 35.True or false: to iron one shirt at a time saves electricity. (a) False (b) True
36. 36.🧾 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?
37. 37.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
38. 38.🔍 Which is the odd one out? (a) run fans in empty rooms (b) unplug idle chargers (c) leave the TV on standby (d) iron one shirt at a time
39. 39.🧾 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?
40. 40.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =

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