Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 154 · 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 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?
2. 2.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
3. 3.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) unplug idle chargers (d) leave fridge door open
4. 4.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use LED lamps (c) run fans in empty rooms (d) leave the TV on standby
5. 5.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
6. 6.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
7. 7.True or false: to use daylight to read saves electricity. (a) True (b) False
8. 8.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) an oil lamp (c) a filament bulb (d) a candle
9. 9.🔍 Which is the odd one out? (a) close the fridge quickly (b) switch off empty rooms (c) leave fridge door open (d) use LED lamps
10. 10.Which of these saves electricity? (a) switch off empty rooms (b) leave the TV on standby (c) leave fridge door open (d) iron one shirt at a time
11. 11.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
12. 12.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
13. 13.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
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 10 hours. How many watt-hours (Wh) are saved?
15. 15.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
16. 16.True or false: to use old filament bulbs wastes electricity. (a) True (b) False
17. 17.True or false: to leave fridge door open saves electricity. (a) True (b) False
18. 18.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) use LED lamps (d) iron one shirt at a time
19. 19.🔍 Which is the odd one out? (a) iron one shirt at a time (b) unplug idle chargers (c) use LED lamps (d) close the fridge quickly
20. 20.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 volt (d) 1 ampere
21. 21.🧾 A family uses 200 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
22. 22.Which of these wastes electricity? (a) close the fridge quickly (b) set the AC to 24 °C (c) unplug idle chargers (d) leave fridge door open
23. 23.Which of these wastes electricity? (a) leave the TV on standby (b) close the fridge quickly (c) switch off empty rooms (d) use daylight to read
24. 24.🔍 Which is the odd one out? (a) leave the TV on standby (b) set the AC to 24 °C (c) use old filament bulbs (d) iron one shirt at a time
25. 25.🔍 Which is the odd one out? (a) unplug idle chargers (b) run fans in empty rooms (c) use old filament bulbs (d) iron one shirt at a time
26. 26.🧾 A family uses 140 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
27. 27.🧾 A family uses 100 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
28. 28.Which of these saves electricity? (a) close the fridge quickly (b) run fans in empty rooms (c) use old filament bulbs (d) leave fridge door open
29. 29.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
30. 30.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
31. 31.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
32. 32.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
33. 33.🧾 A family uses 20 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
34. 34.🧾 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?
35. 35.Which of these saves electricity? (a) use LED lamps (b) leave the TV on standby (c) run fans in empty rooms (d) iron one shirt at a time
36. 36.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
37. 37.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
38. 38.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) set the AC to 24 °C (d) use LED lamps
39. 39.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
40. 40.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?

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