Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 264 · 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 60 W filament bulb is swapped for a 9 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 family uses 170 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
3. 3.🔍 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) close the fridge quickly
4. 4.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
5. 5.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
6. 6.🧾 A family uses 110 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
7. 7.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
8. 8.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
9. 9.Which of these saves electricity? (a) use daylight to read (b) leave the TV on standby (c) leave fridge door open (d) run fans in empty rooms
10. 10.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
11. 11.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
12. 12.True or false: to set the AC to 24 °C wastes electricity. (a) False (b) True
13. 13.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) use old filament bulbs (d) set the AC to 24 °C
14. 14.True or false: to use LED lamps wastes electricity. (a) True (b) False
15. 15.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
16. 16.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
17. 17.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
18. 18.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave fridge door open (c) use daylight to read (d) run fans in empty rooms
19. 19.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
20. 20.🔍 Which is the odd one out? (a) use old filament bulbs (b) switch off empty rooms (c) set the AC to 24 °C (d) close the fridge quickly
21. 21.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) use old filament bulbs (d) use LED lamps
22. 22.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
23. 23.Which of these saves electricity? (a) iron one shirt at a time (b) use LED lamps (c) use old filament bulbs (d) leave the TV on standby
24. 24.🔍 Which is the odd one out? (a) leave fridge door open (b) unplug idle chargers (c) use daylight to read (d) close the fridge quickly
25. 25.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
26. 26.True or false: to use daylight to read wastes electricity. (a) False (b) True
27. 27.True or false: to leave fridge door open wastes electricity. (a) True (b) False
28. 28.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
29. 29.Which of these saves electricity? (a) run fans in empty rooms (b) close the fridge quickly (c) use old filament bulbs (d) iron one shirt at a time
30. 30.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
31. 31.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
32. 32.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
33. 33.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
34. 34.🔍 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
35. 35.🔍 Which is the odd one out? (a) switch off empty rooms (b) iron one shirt at a time (c) use LED lamps (d) unplug idle chargers
36. 36.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
37. 37.🔍 Which is the odd one out? (a) switch off empty rooms (b) run fans in empty rooms (c) leave fridge door open (d) iron one shirt at a time
38. 38.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
39. 39.🔍 Which is the odd one out? (a) run fans in empty rooms (b) use old filament bulbs (c) use LED lamps (d) leave fridge door open
40. 40.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?

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