Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 900 · 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 is the odd one out? (a) use LED lamps (b) close the fridge quickly (c) use old filament bulbs (d) set the AC to 24 °C
2. 2.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
3. 3.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) close the fridge quickly (c) use daylight to read (d) leave the TV on standby
4. 4.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
5. 5.🧾 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?
6. 6.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) unplug idle chargers (d) leave fridge door open
7. 7.Which of these saves electricity? (a) set the AC to 24 °C (b) leave fridge door open (c) leave the TV on standby (d) run fans in empty rooms
8. 8.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) use old filament bulbs (d) close the fridge quickly
9. 9.🧾 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?
10. 10.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 ampere
11. 11.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
12. 12.🧾 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?
13. 13.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
14. 14.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
15. 15.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
16. 16.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
17. 17.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
18. 18.🧾 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?
19. 19.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) an oil lamp (d) a candle
20. 20.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
21. 21.🧾 A family uses 160 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
22. 22.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
23. 23.💡 Does it save or waste electricity to set the AC to 24 °C? (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 use LED lamps wastes electricity. (a) False (b) True
26. 26.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
27. 27.🧾 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?
28. 28.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) switch off empty rooms (d) leave fridge door open
29. 29.Which of these saves electricity? (a) switch off empty rooms (b) leave fridge door open (c) use old filament bulbs (d) iron one shirt at a time
30. 30.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
31. 31.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) use old filament bulbs (d) close the fridge quickly
32. 32.True or false: to use daylight to read wastes electricity. (a) False (b) True
33. 33.🧾 A family uses 100 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
34. 34.True or false: to leave the TV on standby saves electricity. (a) True (b) False
35. 35.🧾 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?
36. 36.🧾 A family uses 80 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
37. 37.🔍 Which is the odd one out? (a) leave fridge door open (b) set the AC to 24 °C (c) use LED lamps (d) switch off empty rooms
38. 38.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
39. 39.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
40. 40.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?

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