Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 347 · 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 unplug idle chargers? (a) saves electricity (b) wastes electricity
2. 2.🧾 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?
3. 3.🧾 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?
4. 4.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) use old filament bulbs (d) use daylight to read
5. 5.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 volt (c) 1 ampere (d) 1 watt
6. 6.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
7. 7.🧾 A 1500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
8. 8.🔍 Which is the odd one out? (a) close the fridge quickly (b) leave fridge door open (c) use LED lamps (d) unplug idle chargers
9. 9.🧾 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?
10. 10.🧾 A family uses 140 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
11. 11.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
12. 12.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
13. 13.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
14. 14.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
15. 15.🧾 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
16. 16.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
17. 17.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
18. 18.Which of these wastes electricity? (a) set the AC to 24 °C (b) iron one shirt at a time (c) close the fridge quickly (d) switch off empty rooms
19. 19.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
20. 20.True or false: to use LED lamps saves electricity. (a) True (b) False
21. 21.🔍 Which is the odd one out? (a) close the fridge quickly (b) run fans in empty rooms (c) use LED lamps (d) switch off empty rooms
22. 22.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
23. 23.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) use daylight to read (d) run fans in empty rooms
24. 24.🧾 A family uses 160 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
25. 25.🧾 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?
26. 26.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
27. 27.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
28. 28.🧾 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?
29. 29.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
30. 30.Which of these saves electricity? (a) use LED lamps (b) leave the TV on standby (c) run fans in empty rooms (d) iron one shirt at a time
31. 31.🧾 A 100 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
32. 32.🔍 Which is the odd one out? (a) leave the TV on standby (b) use LED lamps (c) use old filament bulbs (d) iron one shirt at a time
33. 33.🔍 Which is the odd one out? (a) switch off empty rooms (b) use old filament bulbs (c) close the fridge quickly (d) use LED lamps
34. 34.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
35. 35.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
36. 36.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave fridge door open (c) iron one shirt at a time (d) use old filament bulbs
37. 37.Which of these saves electricity? (a) iron one shirt at a time (b) use old filament bulbs (c) switch off empty rooms (d) leave the TV on standby
38. 38.🧾 A 250 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
39. 39.🧾 A family uses 50 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
40. 40.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?

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