Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 536 · 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 use daylight to read wastes electricity. (a) True (b) False
2. 2.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
3. 3.🧾 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?
4. 4.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
5. 5.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
6. 6.🔍 Which is the odd one out? (a) close the fridge quickly (b) leave the TV on standby (c) run fans in empty rooms (d) leave fridge door open
7. 7.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
8. 8.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
9. 9.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 volt (d) 1 watt
10. 10.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
11. 11.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
12. 12.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) a candle (d) an oil lamp
13. 13.Which of these wastes electricity? (a) unplug idle chargers (b) use LED lamps (c) switch off empty rooms (d) use old filament bulbs
14. 14.🧾 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?
15. 15.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use old filament bulbs (c) unplug idle chargers (d) switch off empty rooms
16. 16.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) iron one shirt at a time (d) switch off empty rooms
17. 17.True or false: to use old filament bulbs 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) close the fridge quickly (b) use LED lamps (c) leave the TV on standby (d) set the AC to 24 °C
20. 20.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
21. 21.🧾 A 1000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
22. 22.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
23. 23.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
24. 24.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
25. 25.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
26. 26.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) leave fridge door open (d) use daylight to read
27. 27.Which of these wastes electricity? (a) run fans in empty rooms (b) close the fridge quickly (c) switch off empty rooms (d) set the AC to 24 °C
28. 28.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) iron one shirt at a time (d) unplug idle chargers
29. 29.Which of these wastes electricity? (a) close the fridge quickly (b) switch off empty rooms (c) iron one shirt at a time (d) use daylight to read
30. 30.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
31. 31.🧾 A family uses 150 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
32. 32.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) use daylight to read (d) leave the TV on standby
33. 33.🧾 A family uses 20 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
34. 34.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
35. 35.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
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 1 hour. How many watt-hours (Wh) are saved?
37. 37.🧾 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?
38. 38.🔍 Which is the odd one out? (a) switch off empty rooms (b) use daylight to read (c) iron one shirt at a time (d) use LED lamps
39. 39.Which of these wastes electricity? (a) leave fridge door open (b) use LED lamps (c) close the fridge quickly (d) switch off empty rooms
40. 40.True or false: to unplug idle chargers saves electricity. (a) False (b) True

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