Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 768 · 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 old filament bulbs (b) run fans in empty rooms (c) use LED lamps (d) iron one shirt at a time
2. 2.Which of these wastes electricity? (a) use daylight to read (b) use LED lamps (c) switch off empty rooms (d) leave fridge door open
3. 3.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
4. 4.🧾 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?
5. 5.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
6. 6.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
7. 7.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
8. 8.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
9. 9.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) leave the TV on standby (d) use old filament bulbs
10. 10.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
11. 11.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
12. 12.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
13. 13.🧾 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
14. 14.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
15. 15.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
16. 16.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
17. 17.🔍 Which is the odd one out? (a) close the fridge quickly (b) leave the TV on standby (c) iron one shirt at a time (d) run fans in empty rooms
18. 18.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
19. 19.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
20. 20.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) leave the TV on standby (d) set the AC to 24 °C
21. 21.True or false: to close the fridge quickly saves electricity. (a) True (b) False
22. 22.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
23. 23.True or false: to unplug idle chargers saves electricity. (a) True (b) False
24. 24.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
25. 25.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
26. 26.Which of these saves electricity? (a) leave the TV on standby (b) unplug idle chargers (c) leave fridge door open (d) iron one shirt at a time
27. 27.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
28. 28.🧾 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?
29. 29.🔍 Which is the odd one out? (a) use daylight to read (b) close the fridge quickly (c) leave the TV on standby (d) switch off empty rooms
30. 30.True or false: to leave fridge door open wastes electricity. (a) False (b) True
31. 31.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave the TV on standby (c) set the AC to 24 °C (d) iron one shirt at a time
32. 32.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
33. 33.True or false: to switch off empty rooms saves electricity. (a) True (b) False
34. 34.🧾 A family uses 60 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
35. 35.Which of these wastes electricity? (a) close the fridge quickly (b) set the AC to 24 °C (c) switch off empty rooms (d) run fans in empty rooms
36. 36.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
37. 37.🧾 A family uses 50 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
38. 38.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
39. 39.Which of these wastes electricity? (a) leave the TV on standby (b) use LED lamps (c) unplug idle chargers (d) switch off empty rooms
40. 40.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =

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