Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 991 · 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.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
2. 2.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
3. 3.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
4. 4.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) close the fridge quickly (d) leave fridge door open
5. 5.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
6. 6.🧾 A 1000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
7. 7.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
8. 8.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 watt
9. 9.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) close the fridge quickly (d) run fans in empty rooms
10. 10.True or false: to use LED lamps saves electricity. (a) False (b) True
11. 11.🔍 Which is the odd one out? (a) run fans in empty rooms (b) iron one shirt at a time (c) use old filament bulbs (d) unplug idle chargers
12. 12.True or false: to close the fridge quickly saves electricity. (a) False (b) True
13. 13.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
14. 14.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
15. 15.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
16. 16.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
17. 17.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) switch off empty rooms (d) iron one shirt at a time
18. 18.🧾 A family uses 70 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
19. 19.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
20. 20.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
21. 21.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) leave the TV on standby (d) use old filament bulbs
22. 22.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
23. 23.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) use LED lamps (d) iron one shirt at a time
24. 24.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) leave fridge door open (d) use daylight to read
25. 25.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
26. 26.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
27. 27.Which of these saves electricity? (a) run fans in empty rooms (b) use LED lamps (c) leave fridge door open (d) use old filament bulbs
28. 28.🧾 A family uses 160 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
29. 29.🧾 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?
30. 30.Which of these wastes electricity? (a) close the fridge quickly (b) use old filament bulbs (c) use daylight to read (d) set the AC to 24 °C
31. 31.🧾 A family uses 200 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
32. 32.Which of these wastes electricity? (a) unplug idle chargers (b) set the AC to 24 °C (c) run fans in empty rooms (d) switch off empty rooms
33. 33.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
34. 34.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
35. 35.True or false: to use daylight to read saves electricity. (a) False (b) True
36. 36.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
37. 37.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
38. 38.🧾 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?
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 7 hours. How many watt-hours (Wh) are saved?
40. 40.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =

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