Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 192 · 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.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 watt (d) 1 kilowatt-hour (kWh)
2. 2.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
3. 3.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
4. 4.🔍 Which is the odd one out? (a) use LED lamps (b) switch off empty rooms (c) leave fridge door open (d) unplug idle chargers
5. 5.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
6. 6.🧾 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?
7. 7.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
8. 8.True or false: to leave fridge door open wastes electricity. (a) False (b) True
9. 9.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a candle (c) a filament bulb (d) an LED lamp
10. 10.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
11. 11.Which of these wastes electricity? (a) use LED lamps (b) use daylight to read (c) switch off empty rooms (d) iron one shirt at a time
12. 12.🧾 A 250 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
13. 13.Which of these saves electricity? (a) use old filament bulbs (b) close the fridge quickly (c) leave fridge door open (d) run fans in empty rooms
14. 14.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
15. 15.Which of these wastes electricity? (a) close the fridge quickly (b) leave fridge door open (c) use LED lamps (d) set the AC to 24 °C
16. 16.Which of these wastes electricity? (a) run fans in empty rooms (b) unplug idle chargers (c) close the fridge quickly (d) switch off empty rooms
17. 17.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
18. 18.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
19. 19.🔍 Which is the odd one out? (a) leave fridge door open (b) run fans in empty rooms (c) leave the TV on standby (d) use daylight to read
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 10 hours. How many watt-hours (Wh) are saved?
21. 21.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) leave fridge door open (d) leave the TV on standby
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 1 hour. How many watt-hours (Wh) are saved?
23. 23.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) leave fridge door open (d) unplug idle chargers
24. 24.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
25. 25.🧾 A family uses 140 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
26. 26.True or false: to close the fridge quickly saves electricity. (a) False (b) True
27. 27.True or false: to switch off empty rooms saves electricity. (a) False (b) True
28. 28.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
29. 29.🧾 A 250 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
30. 30.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) leave the TV on standby (d) set the AC to 24 °C
31. 31.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
32. 32.🧾 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?
33. 33.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
34. 34.🧾 A 2000 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
35. 35.Which of these saves electricity? (a) iron one shirt at a time (b) leave the TV on standby (c) switch off empty rooms (d) use old filament bulbs
36. 36.Which of these saves electricity? (a) iron one shirt at a time (b) use daylight to read (c) run fans in empty rooms (d) use old filament bulbs
37. 37.True or false: to use daylight to read wastes electricity. (a) True (b) False
38. 38.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
39. 39.Which of these saves electricity? (a) use LED lamps (b) run fans in empty rooms (c) leave the TV on standby (d) leave fridge door open
40. 40.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?

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