Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 300 · 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 leave fridge door open? (a) wastes electricity (b) saves electricity
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
3. 3.🔍 Which is the odd one out? (a) leave the TV on standby (b) unplug idle chargers (c) iron one shirt at a time (d) leave fridge door open
4. 4.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an LED lamp (c) a filament bulb (d) an oil lamp
5. 5.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
6. 6.🧾 A 500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
7. 7.Which of these wastes electricity? (a) run fans in empty rooms (b) use daylight to read (c) close the fridge quickly (d) unplug idle chargers
8. 8.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
9. 9.🧾 A family uses 90 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
10. 10.🔍 Which is the odd one out? (a) use LED lamps (b) use old filament bulbs (c) close the fridge quickly (d) unplug idle chargers
11. 11.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
12. 12.Which of these saves electricity? (a) switch off empty rooms (b) use old filament bulbs (c) iron one shirt at a time (d) leave the TV on standby
13. 13.🧾 A family uses 120 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
15. 15.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
16. 16.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
17. 17.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) use daylight to read (d) iron one shirt at a time
18. 18.Which of these saves electricity? (a) run fans in empty rooms (b) use LED lamps (c) leave the TV on standby (d) iron one shirt at a time
19. 19.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
20. 20.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
21. 21.Which of these wastes electricity? (a) close the fridge quickly (b) use daylight to read (c) leave fridge door open (d) set the AC to 24 °C
22. 22.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
23. 23.Which of these wastes electricity? (a) leave the TV on standby (b) use daylight to read (c) use LED lamps (d) close the fridge quickly
24. 24.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
25. 25.Which of these saves electricity? (a) run fans in empty rooms (b) use old filament bulbs (c) iron one shirt at a time (d) close the fridge quickly
26. 26.True or false: to leave the TV on standby wastes electricity. (a) True (b) False
27. 27.🧾 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?
28. 28.🔍 Which is the odd one out? (a) use LED lamps (b) leave fridge door open (c) leave the TV on standby (d) use old filament bulbs
29. 29.🧾 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?
30. 30.True or false: to leave fridge door open wastes electricity. (a) False (b) True
31. 31.Which of these saves electricity? (a) set the AC to 24 °C (b) run fans in empty rooms (c) iron one shirt at a time (d) use old filament bulbs
32. 32.True or false: to switch off empty rooms saves electricity. (a) False (b) True
33. 33.Which of these wastes electricity? (a) use daylight to read (b) close the fridge quickly (c) use old filament bulbs (d) unplug idle chargers
34. 34.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
35. 35.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) switch off empty rooms (d) run fans in empty rooms
36. 36.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
37. 37.🧾 A family uses 100 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
38. 38.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) iron one shirt at a time (d) unplug idle chargers
39. 39.🧾 A family uses 80 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
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 1 hour. How many watt-hours (Wh) are saved?

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