Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 445 · 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 is the odd one out? (a) run fans in empty rooms (b) close the fridge quickly (c) use old filament bulbs (d) iron one shirt at a time
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 kilowatt-hour (kWh) (b) 1 ampere (c) 1 watt (d) 1 volt
3. 3.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
4. 4.🧾 A family uses 110 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
5. 5.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
6. 6.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
7. 7.Which of these wastes electricity? (a) close the fridge quickly (b) set the AC to 24 °C (c) unplug idle chargers (d) leave fridge door open
8. 8.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
9. 9.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
10. 10.🔍 Which is the odd one out? (a) use daylight to read (b) use old filament bulbs (c) leave fridge door open (d) iron one shirt at a time
11. 11.🧾 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?
12. 12.True or false: to unplug idle chargers saves electricity. (a) True (b) False
13. 13.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
14. 14.🧾 A family uses 70 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
15. 15.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
16. 16.True or false: to use old filament bulbs saves electricity. (a) True (b) False
17. 17.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
18. 18.Which of these saves electricity? (a) use old filament bulbs (b) unplug idle chargers (c) run fans in empty rooms (d) leave fridge door open
19. 19.🧾 A 500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
20. 20.True or false: to close the fridge quickly saves electricity. (a) False (b) True
21. 21.🧾 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?
22. 22.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
23. 23.🔍 Which is the odd one out? (a) iron one shirt at a time (b) set the AC to 24 °C (c) use old filament bulbs (d) run fans in empty rooms
24. 24.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) use old filament bulbs (d) close the fridge quickly
25. 25.Which of these wastes electricity? (a) use daylight to read (b) run fans in empty rooms (c) use LED lamps (d) switch off empty rooms
26. 26.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
27. 27.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
28. 28.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an oil lamp (c) a filament bulb (d) an LED lamp
29. 29.🔍 Which is the odd one out? (a) switch off empty rooms (b) close the fridge quickly (c) set the AC to 24 °C (d) leave fridge door open
30. 30.True or false: to use daylight to read wastes electricity. (a) True (b) False
31. 31.True or false: to use LED lamps wastes electricity. (a) False (b) True
32. 32.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
33. 33.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
34. 34.🔍 Which is the odd one out? (a) leave the TV on standby (b) run fans in empty rooms (c) use old filament bulbs (d) unplug idle chargers
35. 35.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
36. 36.Which of these saves electricity? (a) run fans in empty rooms (b) use old filament bulbs (c) switch off empty rooms (d) iron one shirt at a time
37. 37.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
38. 38.Which of these wastes electricity? (a) close the fridge quickly (b) switch off empty rooms (c) set the AC to 24 °C (d) iron one shirt at a time
39. 39.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use LED lamps (c) leave fridge door open (d) use old filament bulbs
40. 40.🧾 A 1000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =

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