Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 430 · 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.🔍 Which is the odd one out? (a) run fans in empty rooms (b) unplug idle chargers (c) use old filament bulbs (d) leave fridge door open
2. 2.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) switch off empty rooms (d) run fans in empty rooms
3. 3.Which of these wastes electricity? (a) switch off empty rooms (b) leave fridge door open (c) use daylight to read (d) use LED lamps
4. 4.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
5. 5.🔍 Which is the odd one out? (a) close the fridge quickly (b) use old filament bulbs (c) use daylight to read (d) set the AC to 24 °C
6. 6.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
7. 7.🧾 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
8. 8.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
9. 9.💡 Does it save or waste electricity to unplug idle chargers? (a) saves electricity (b) wastes electricity
10. 10.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
11. 11.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
12. 12.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 ampere
13. 13.🧾 A 500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
14. 14.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) close the fridge quickly (d) iron one shirt at a time
15. 15.🔍 Which is the odd one out? (a) switch off empty rooms (b) use daylight to read (c) run fans in empty rooms (d) use LED lamps
16. 16.🔍 Which is the odd one out? (a) iron one shirt at a time (b) unplug idle chargers (c) close the fridge quickly (d) switch off empty rooms
17. 17.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) leave fridge door open (d) use daylight to read
18. 18.🧾 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?
19. 19.🧾 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?
20. 20.🧾 A family uses 80 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
21. 21.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
22. 22.🧾 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?
23. 23.🧾 A family uses 170 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
24. 24.🧾 A family uses 190 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
25. 25.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
26. 26.True or false: to iron one shirt at a time saves electricity. (a) False (b) True
27. 27.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
28. 28.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
29. 29.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
30. 30.🔍 Which is the odd one out? (a) leave fridge door open (b) use daylight to read (c) use old filament bulbs (d) leave the TV on standby
31. 31.🔍 Which is the odd one out? (a) unplug idle chargers (b) use LED lamps (c) switch off empty rooms (d) leave the TV on standby
32. 32.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave the TV on standby (c) leave fridge door open (d) use LED lamps
33. 33.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
34. 34.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
35. 35.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
36. 36.Which of these wastes electricity? (a) use LED lamps (b) close the fridge quickly (c) unplug idle chargers (d) leave the TV on standby
37. 37.🧾 A family uses 110 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
38. 38.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
39. 39.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) use old filament bulbs (d) close the fridge quickly
40. 40.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?

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