Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 405 · 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 8 hours. How many watt-hours (Wh) are saved?
2. 2.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) close the fridge quickly (d) use daylight to read
3. 3.Which of these saves electricity? (a) leave fridge door open (b) iron one shirt at a time (c) use old filament bulbs (d) unplug idle chargers
4. 4.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
5. 5.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
6. 6.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
7. 7.Which of these wastes electricity? (a) use daylight to read (b) use old filament bulbs (c) switch off empty rooms (d) use LED lamps
8. 8.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
9. 9.🧾 A family uses 170 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
10. 10.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) switch off empty rooms (d) use old filament bulbs
11. 11.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave the TV on standby (c) switch off empty rooms (d) leave fridge door open
12. 12.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
13. 13.True or false: to close the fridge quickly saves electricity. (a) True (b) False
14. 14.🧾 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?
15. 15.🧾 A family uses 30 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
16. 16.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) iron one shirt at a time (d) use LED lamps
17. 17.🔍 Which is the odd one out? (a) use LED lamps (b) leave fridge door open (c) switch off empty rooms (d) unplug idle chargers
18. 18.🧾 A 50 W appliance runs for 6 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.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
21. 21.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 volt
22. 22.🧾 A family uses 100 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
23. 23.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
24. 24.True or false: to use daylight to read wastes electricity. (a) False (b) True
25. 25.🧾 A family uses 120 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
26. 26.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) an oil lamp (c) a candle (d) a filament bulb
27. 27.True or false: to use daylight to read saves electricity. (a) False (b) True
28. 28.🧾 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?
29. 29.Which of these wastes electricity? (a) use LED lamps (b) unplug idle chargers (c) switch off empty rooms (d) run fans in empty rooms
30. 30.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
31. 31.🔍 Which is the odd one out? (a) unplug idle chargers (b) close the fridge quickly (c) leave the TV on standby (d) use daylight to read
32. 32.🧾 A family uses 70 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
33. 33.Which of these saves electricity? (a) set the AC to 24 °C (b) leave the TV on standby (c) use old filament bulbs (d) iron one shirt at a time
34. 34.🧾 A family uses 200 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
35. 35.🧾 A 2000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
36. 36.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
37. 37.Which of these wastes electricity? (a) set the AC to 24 °C (b) iron one shirt at a time (c) close the fridge quickly (d) use LED lamps
38. 38.Which of these wastes electricity? (a) switch off empty rooms (b) unplug idle chargers (c) close the fridge quickly (d) leave fridge door open
39. 39.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
40. 40.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?

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