Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 807 · 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 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 watt (c) 1 ampere (d) 1 volt
3. 3.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) use LED lamps (d) use old filament bulbs
4. 4.🧾 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?
5. 5.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
6. 6.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
7. 7.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
8. 8.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
9. 9.🧾 A family uses 140 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
10. 10.🔍 Which is the odd one out? (a) switch off empty rooms (b) use LED lamps (c) leave the TV on standby (d) close the fridge quickly
11. 11.True or false: to use old filament bulbs saves electricity. (a) False (b) True
12. 12.🧾 A family uses 20 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
13. 13.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) unplug idle chargers (d) leave the TV on standby
14. 14.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
15. 15.🔍 Which is the odd one out? (a) run fans in empty rooms (b) switch off empty rooms (c) unplug idle chargers (d) use LED lamps
16. 16.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) leave the TV on standby (c) use old filament bulbs (d) leave fridge door open
17. 17.🔍 Which is the odd one out? (a) use old filament bulbs (b) unplug idle chargers (c) close the fridge quickly (d) use daylight to read
18. 18.🧾 A family uses 60 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
19. 19.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an oil lamp (c) a candle (d) an LED lamp
20. 20.Which of these wastes electricity? (a) set the AC to 24 °C (b) use LED lamps (c) unplug idle chargers (d) iron one shirt at a time
21. 21.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
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 6 hours. How many watt-hours (Wh) are saved?
23. 23.🧾 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?
24. 24.True or false: to leave fridge door open wastes electricity. (a) True (b) False
25. 25.🧾 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?
26. 26.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) leave fridge door open (d) unplug idle chargers
27. 27.🧾 A 1500 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
28. 28.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
29. 29.🧾 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?
30. 30.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
31. 31.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
32. 32.🔍 Which is the odd one out? (a) use LED lamps (b) iron one shirt at a time (c) use daylight to read (d) set the AC to 24 °C
33. 33.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
34. 34.Which of these wastes electricity? (a) close the fridge quickly (b) unplug idle chargers (c) set the AC to 24 °C (d) leave fridge door open
35. 35.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
36. 36.🧾 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?
37. 37.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
38. 38.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
39. 39.🧾 A family uses 200 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
40. 40.🧾 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?

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