Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 910 · 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 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?
2. 2.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
3. 3.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
4. 4.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
5. 5.🔍 Which is the odd one out? (a) use old filament bulbs (b) unplug idle chargers (c) set the AC to 24 °C (d) switch off empty rooms
6. 6.🧾 A family uses 40 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
7. 7.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
8. 8.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
9. 9.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
10. 10.🧾 A 1500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
11. 11.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
12. 12.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
13. 13.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) use daylight to read (d) use old filament bulbs
14. 14.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
15. 15.Which of these wastes electricity? (a) use daylight to read (b) leave fridge door open (c) set the AC to 24 °C (d) unplug idle chargers
16. 16.True or false: to use old filament bulbs saves electricity. (a) True (b) False
17. 17.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
18. 18.Which of these wastes electricity? (a) iron one shirt at a time (b) use daylight to read (c) switch off empty rooms (d) unplug idle chargers
19. 19.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
20. 20.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
21. 21.True or false: to use LED lamps saves electricity. (a) True (b) False
22. 22.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
23. 23.🧾 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?
24. 24.True or false: to unplug idle chargers saves electricity. (a) True (b) False
25. 25.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) close the fridge quickly (d) run fans in empty rooms
26. 26.🧾 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
27. 27.🔍 Which is the odd one out? (a) use LED lamps (b) run fans in empty rooms (c) leave fridge door open (d) leave the TV on standby
28. 28.🔍 Which is the odd one out? (a) use LED lamps (b) set the AC to 24 °C (c) iron one shirt at a time (d) unplug idle chargers
29. 29.🔍 Which is the odd one out? (a) use LED lamps (b) use daylight to read (c) switch off empty rooms (d) leave fridge door open
30. 30.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
31. 31.🧾 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?
32. 32.🧾 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?
33. 33.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
34. 34.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) iron one shirt at a time (d) use daylight to read
35. 35.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
36. 36.🧾 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?
37. 37.🧾 A family uses 160 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
38. 38.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) switch off empty rooms (d) iron one shirt at a time
39. 39.Which of these saves electricity? (a) unplug idle chargers (b) leave the TV on standby (c) use old filament bulbs (d) leave fridge door open
40. 40.Which of these wastes electricity? (a) close the fridge quickly (b) leave the TV on standby (c) switch off empty rooms (d) use LED lamps

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