Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 328 · 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 4 hours. How many watt-hours (Wh) are saved?
2. 2.🧾 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?
3. 3.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) use LED lamps (d) switch off empty rooms
4. 4.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
5. 5.Which of these wastes electricity? (a) close the fridge quickly (b) use daylight to read (c) use old filament bulbs (d) switch off empty rooms
6. 6.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 volt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
7. 7.Which of these wastes electricity? (a) unplug idle chargers (b) use LED lamps (c) close the fridge quickly (d) run fans in empty rooms
8. 8.🧾 A family uses 150 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
9. 9.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
10. 10.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) unplug idle chargers (d) use old filament bulbs
11. 11.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) use old filament bulbs (d) use LED lamps
12. 12.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use LED lamps (c) switch off empty rooms (d) set the AC to 24 °C
13. 13.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) a filament bulb (d) an oil lamp
14. 14.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) switch off empty rooms (d) leave the TV on standby
15. 15.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) use daylight to read (d) leave fridge door open
16. 16.🧾 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?
17. 17.True or false: to leave the TV on standby saves electricity. (a) True (b) False
18. 18.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) leave fridge door open (d) use LED lamps
19. 19.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
20. 20.🧾 A family uses 30 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
21. 21.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
22. 22.Which of these wastes electricity? (a) switch off empty rooms (b) leave fridge door open (c) use LED lamps (d) unplug idle chargers
23. 23.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
24. 24.🧾 A family uses 180 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
25. 25.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) unplug idle chargers (c) run fans in empty rooms (d) use daylight to read
26. 26.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
27. 27.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
28. 28.🔍 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) close the fridge quickly
29. 29.🔍 Which is the odd one out? (a) leave fridge door open (b) iron one shirt at a time (c) unplug idle chargers (d) leave the TV on standby
30. 30.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
31. 31.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
32. 32.🧾 A family uses 190 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
33. 33.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
34. 34.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) close the fridge quickly (d) iron one shirt at a time
35. 35.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
36. 36.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
37. 37.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
38. 38.🧾 A family uses 150 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
39. 39.🧾 A family uses 20 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
40. 40.True or false: to use daylight to read wastes electricity. (a) True (b) False

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