Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 640 · 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.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) switch off empty rooms (d) leave fridge door open
3. 3.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
4. 4.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
5. 5.🧾 A family uses 60 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
6. 6.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
7. 7.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
8. 8.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 watt
9. 9.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
10. 10.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) unplug idle chargers (d) iron one shirt at a time
11. 11.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
12. 12.🔍 Which is the odd one out? (a) leave fridge door open (b) unplug idle chargers (c) leave the TV on standby (d) iron one shirt at a time
13. 13.🔍 Which is the odd one out? (a) unplug idle chargers (b) switch off empty rooms (c) leave fridge door open (d) use LED lamps
14. 14.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) iron one shirt at a time (d) switch off empty rooms
15. 15.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
16. 16.🧾 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?
17. 17.Which of these wastes electricity? (a) use old filament bulbs (b) use LED lamps (c) set the AC to 24 °C (d) use daylight to read
18. 18.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
19. 19.True or false: to leave fridge door open saves electricity. (a) True (b) False
20. 20.Which of these saves electricity? (a) unplug idle chargers (b) leave fridge door open (c) iron one shirt at a time (d) use old filament bulbs
21. 21.Which of these wastes electricity? (a) set the AC to 24 °C (b) run fans in empty rooms (c) unplug idle chargers (d) use LED lamps
22. 22.🔍 Which is the odd one out? (a) iron one shirt at a time (b) unplug idle chargers (c) set the AC to 24 °C (d) use LED lamps
23. 23.🔍 Which is the odd one out? (a) use old filament bulbs (b) use daylight to read (c) unplug idle chargers (d) use LED lamps
24. 24.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
25. 25.Which of these saves electricity? (a) run fans in empty rooms (b) use daylight to read (c) leave the TV on standby (d) iron one shirt at a time
26. 26.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
27. 27.🔍 Which is the odd one out? (a) use LED lamps (b) use old filament bulbs (c) leave the TV on standby (d) leave fridge door open
28. 28.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
29. 29.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
30. 30.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) close the fridge quickly (d) leave fridge door open
31. 31.🧾 A family uses 120 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
32. 32.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
33. 33.True or false: to use LED lamps saves electricity. (a) False (b) True
34. 34.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
35. 35.Which of these saves electricity? (a) use LED lamps (b) run fans in empty rooms (c) use old filament bulbs (d) leave fridge door open
36. 36.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
37. 37.🧾 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?
38. 38.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
39. 39.🔍 Which is the odd one out? (a) use old filament bulbs (b) switch off empty rooms (c) leave fridge door open (d) iron one shirt at a time
40. 40.True or false: to switch off empty rooms saves electricity. (a) False (b) True

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids