Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 45 · 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.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) leave the TV on standby (d) switch off empty rooms
2. 2.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
3. 3.🔍 Which is the odd one out? (a) use LED lamps (b) run fans in empty rooms (c) iron one shirt at a time (d) leave the TV on standby
4. 4.Which of these saves electricity? (a) unplug idle chargers (b) run fans in empty rooms (c) use old filament bulbs (d) leave the TV on standby
5. 5.Which of these wastes electricity? (a) switch off empty rooms (b) leave the TV on standby (c) close the fridge quickly (d) set the AC to 24 °C
6. 6.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
7. 7.Which of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) use old filament bulbs (d) leave fridge door open
8. 8.🔍 Which is the odd one out? (a) use LED lamps (b) iron one shirt at a time (c) switch off empty rooms (d) use daylight to read
9. 9.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
10. 10.Which of these wastes electricity? (a) unplug idle chargers (b) use old filament bulbs (c) set the AC to 24 °C (d) use LED lamps
11. 11.🧾 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
12. 12.🧾 A family uses 90 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
13. 13.🧾 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?
14. 14.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
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 9 hours. How many watt-hours (Wh) are saved?
16. 16.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
17. 17.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
18. 18.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
19. 19.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) iron one shirt at a time (c) leave fridge door open (d) use old filament bulbs
20. 20.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
21. 21.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
22. 22.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
23. 23.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
24. 24.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) run fans in empty rooms (d) leave the TV on standby
25. 25.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
26. 26.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
27. 27.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
28. 28.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
29. 29.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
30. 30.True or false: to use LED lamps wastes electricity. (a) False (b) True
31. 31.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) leave fridge door open (d) set the AC to 24 °C
32. 32.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) run fans in empty rooms (d) set the AC to 24 °C
33. 33.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
34. 34.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
35. 35.True or false: to use daylight to read wastes electricity. (a) False (b) True
36. 36.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
37. 37.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
38. 38.🧾 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?
39. 39.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
40. 40.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =

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