Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 282 · 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 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?
2. 2.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
3. 3.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) an LED lamp (d) a filament bulb
4. 4.🔍 Which is the odd one out? (a) use daylight to read (b) use LED lamps (c) iron one shirt at a time (d) set the AC to 24 °C
5. 5.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) close the fridge quickly (c) use daylight to read (d) leave fridge door open
6. 6.True or false: to use old filament bulbs saves electricity. (a) False (b) True
7. 7.🔍 Which is the odd one out? (a) run fans in empty rooms (b) unplug idle chargers (c) switch off empty rooms (d) use daylight to read
8. 8.🧾 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?
9. 9.🧾 A family uses 80 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
10. 10.🧾 A family uses 80 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
11. 11.🧾 A 50 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
12. 12.🧾 A 1000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
13. 13.Which of these wastes electricity? (a) use daylight to read (b) unplug idle chargers (c) leave fridge door open (d) switch off empty rooms
14. 14.🔍 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) close the fridge quickly
15. 15.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) switch off empty rooms (d) iron one shirt at a time
16. 16.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 ampere (d) 1 kilowatt-hour (kWh)
17. 17.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
18. 18.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
19. 19.🧾 A family uses 170 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
20. 20.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
21. 21.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
22. 22.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
23. 23.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) use LED lamps (d) run fans in empty rooms
24. 24.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
25. 25.🔍 Which is the odd one out? (a) use daylight to read (b) leave the TV on standby (c) switch off empty rooms (d) use LED lamps
26. 26.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
27. 27.True or false: to use LED lamps wastes electricity. (a) False (b) True
28. 28.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) use old filament bulbs (d) unplug idle chargers
29. 29.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
30. 30.True or false: to close the fridge quickly saves electricity. (a) True (b) False
31. 31.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
32. 32.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
33. 33.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
34. 34.Which of these wastes electricity? (a) switch off empty rooms (b) run fans in empty rooms (c) close the fridge quickly (d) use daylight to read
35. 35.Which of these saves electricity? (a) use old filament bulbs (b) iron one shirt at a time (c) run fans in empty rooms (d) use daylight to read
36. 36.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
37. 37.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use old filament bulbs (c) use daylight to read (d) leave fridge door open
38. 38.True or false: to leave fridge door open wastes electricity. (a) False (b) True
39. 39.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
40. 40.🧾 A family uses 190 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?

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