Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 431 · 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 7 hours. How many watt-hours (Wh) are saved?
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
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 4 hours. How many watt-hours (Wh) are saved?
4. 4.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) set the AC to 24 °C (d) leave the TV on standby
5. 5.Which of these wastes electricity? (a) use daylight to read (b) leave fridge door open (c) close the fridge quickly (d) set the AC to 24 °C
6. 6.True or false: to switch off empty rooms saves electricity. (a) False (b) True
7. 7.Which of these saves electricity? (a) unplug idle chargers (b) leave fridge door open (c) leave the TV on standby (d) run fans in empty rooms
8. 8.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
9. 9.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
10. 10.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) close the fridge quickly (c) leave the TV on standby (d) use LED lamps
11. 11.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
12. 12.True or false: to use daylight to read saves electricity. (a) False (b) True
13. 13.True or false: to leave fridge door open wastes electricity. (a) False (b) True
14. 14.🧾 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
15. 15.Which of these wastes electricity? (a) switch off empty rooms (b) run fans in empty rooms (c) use LED lamps (d) use daylight to read
16. 16.Which of these wastes electricity? (a) leave the TV on standby (b) use daylight to read (c) switch off empty rooms (d) set the AC to 24 °C
17. 17.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
18. 18.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
19. 19.Which of these saves electricity? (a) leave fridge door open (b) use LED lamps (c) iron one shirt at a time (d) leave the TV on standby
20. 20.True or false: to use LED lamps saves electricity. (a) True (b) False
21. 21.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
22. 22.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
23. 23.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
24. 24.🧾 A family uses 90 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
25. 25.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
26. 26.🧾 A family uses 160 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
27. 27.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
28. 28.🔍 Which is the odd one out? (a) close the fridge quickly (b) switch off empty rooms (c) run fans in empty rooms (d) set the AC to 24 °C
29. 29.True or false: to leave the TV on standby saves electricity. (a) True (b) False
30. 30.🧾 A family uses 180 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
31. 31.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
32. 32.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
33. 33.True or false: to use daylight to read wastes electricity. (a) True (b) False
34. 34.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
35. 35.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
36. 36.🧾 A family uses 80 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
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 9 hours. How many watt-hours (Wh) are saved?
38. 38.🧾 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?
39. 39.🧾 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?
40. 40.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) use LED lamps (d) use old filament bulbs

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