Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 234 · 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 10 hours. How many watt-hours (Wh) are saved?
2. 2.🧾 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?
3. 3.Which of these saves electricity? (a) unplug idle chargers (b) iron one shirt at a time (c) use old filament bulbs (d) leave the TV on standby
4. 4.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) use LED lamps
5. 5.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
6. 6.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
7. 7.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
8. 8.🔍 Which is the odd one out? (a) leave fridge door open (b) set the AC to 24 °C (c) use daylight to read (d) use LED lamps
9. 9.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
10. 10.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
11. 11.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) iron one shirt at a time (d) close the fridge quickly
12. 12.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
13. 13.🧾 A family uses 150 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
15. 15.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave the TV on standby (c) run fans in empty rooms (d) switch off empty rooms
16. 16.🧾 A family uses 120 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
17. 17.🧾 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
18. 18.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
19. 19.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) leave the TV on standby (d) set the AC to 24 °C
20. 20.🧾 A family uses 20 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
21. 21.🔍 Which is the odd one out? (a) use old filament bulbs (b) unplug idle chargers (c) switch off empty rooms (d) use LED lamps
22. 22.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
23. 23.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
24. 24.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
25. 25.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
26. 26.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
27. 27.True or false: to unplug idle chargers saves electricity. (a) True (b) False
28. 28.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
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.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
31. 31.🧾 A family uses 80 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
32. 32.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) use daylight to read (d) leave the TV on standby
33. 33.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) use daylight to read (d) leave the TV on standby
34. 34.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
35. 35.True or false: to close the fridge quickly saves electricity. (a) False (b) True
36. 36.🔍 Which is the odd one out? (a) unplug idle chargers (b) switch off empty rooms (c) use LED lamps (d) run fans in empty rooms
37. 37.Which of these wastes electricity? (a) unplug idle chargers (b) use LED lamps (c) set the AC to 24 °C (d) run fans in empty rooms
38. 38.True or false: to use daylight to read wastes electricity. (a) False (b) True
39. 39.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
40. 40.True or false: to use daylight to read saves electricity. (a) False (b) True

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