Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 765 · 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 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?
2. 2.Which of these wastes electricity? (a) use old filament bulbs (b) switch off empty rooms (c) set the AC to 24 °C (d) close the fridge quickly
3. 3.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
4. 4.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) a filament bulb (d) an LED lamp
5. 5.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) use LED lamps (d) use old filament bulbs
6. 6.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
7. 7.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) set the AC to 24 °C (d) leave fridge door open
8. 8.🔍 Which is the odd one out? (a) run fans in empty rooms (b) close the fridge quickly (c) switch off empty rooms (d) set the AC to 24 °C
9. 9.🧾 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?
10. 10.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
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) leave the TV on standby
12. 12.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
13. 13.🧾 A family uses 40 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 ampere
15. 15.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) use old filament bulbs (d) close the fridge quickly
16. 16.🧾 A 500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
17. 17.True or false: to use LED lamps wastes electricity. (a) True (b) False
18. 18.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
19. 19.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) use daylight to read (d) leave the TV on standby
20. 20.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
21. 21.🔍 Which is the odd one out? (a) unplug idle chargers (b) use LED lamps (c) use daylight to read (d) iron one shirt at a time
22. 22.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave the TV on standby (c) use LED lamps (d) iron one shirt at a time
23. 23.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
24. 24.Which of these wastes electricity? (a) unplug idle chargers (b) close the fridge quickly (c) run fans in empty rooms (d) switch off empty rooms
25. 25.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
26. 26.Which of these wastes electricity? (a) leave the TV on standby (b) use daylight to read (c) set the AC to 24 °C (d) unplug idle chargers
27. 27.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
28. 28.🧾 A family uses 180 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
29. 29.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
30. 30.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
31. 31.🔍 Which is the odd one out? (a) switch off empty rooms (b) leave fridge door open (c) iron one shirt at a time (d) leave the TV on standby
32. 32.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) use old filament bulbs (d) set the AC to 24 °C
33. 33.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
34. 34.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
35. 35.🧾 A family uses 110 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
36. 36.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
37. 37.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
38. 38.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
39. 39.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
40. 40.True or false: to leave fridge door open wastes electricity. (a) False (b) True

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