Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 209 · 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 of these wastes electricity? (a) leave the TV on standby (b) use LED lamps (c) set the AC to 24 °C (d) switch off empty rooms
2. 2.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
3. 3.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a filament bulb (d) a candle
4. 4.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
5. 5.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
6. 6.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) leave fridge door open (d) use daylight to read
7. 7.🧾 A family uses 70 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
8. 8.Which of these wastes electricity? (a) close the fridge quickly (b) use daylight to read (c) iron one shirt at a time (d) switch off empty rooms
9. 9.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) leave the TV on standby (d) use daylight to read
10. 10.🔍 Which is the odd one out? (a) use daylight to read (b) leave fridge door open (c) set the AC to 24 °C (d) switch off empty rooms
11. 11.True or false: to leave fridge door open saves electricity. (a) False (b) True
12. 12.🧾 A family uses 70 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
13. 13.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
14. 14.Which of these saves electricity? (a) leave the TV on standby (b) unplug idle chargers (c) run fans in empty rooms (d) use old filament bulbs
15. 15.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
16. 16.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
17. 17.🧾 A family uses 200 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
18. 18.True or false: to use daylight to read saves electricity. (a) False (b) True
19. 19.🧾 A family uses 180 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
20. 20.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
21. 21.Which of these saves electricity? (a) run fans in empty rooms (b) switch off empty rooms (c) iron one shirt at a time (d) leave fridge door open
22. 22.True or false: to close the fridge quickly saves electricity. (a) True (b) False
23. 23.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
24. 24.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
25. 25.True or false: to use old filament bulbs saves electricity. (a) False (b) True
26. 26.🔍 Which is the odd one out? (a) close the fridge quickly (b) set the AC to 24 °C (c) unplug idle chargers (d) use old filament bulbs
27. 27.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
28. 28.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
29. 29.🧾 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?
30. 30.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
31. 31.True or false: to set the AC to 24 °C wastes electricity. (a) False (b) True
32. 32.Which of these wastes electricity? (a) switch off empty rooms (b) leave fridge door open (c) unplug idle chargers (d) close the fridge quickly
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 1 hour. How many watt-hours (Wh) are saved?
34. 34.🧾 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?
35. 35.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
36. 36.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
37. 37.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
38. 38.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
39. 39.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
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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