Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 88 · 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.True or false: to leave fridge door open wastes electricity. (a) False (b) True
2. 2.🔍 Which is the odd one out? (a) run fans in empty rooms (b) unplug idle chargers (c) iron one shirt at a time (d) leave the TV on standby
3. 3.🔍 Which is the odd one out? (a) run fans in empty rooms (b) use daylight to read (c) iron one shirt at a time (d) use old filament bulbs
4. 4.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
5. 5.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
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 4 hours. How many watt-hours (Wh) are saved?
7. 7.🧾 A family uses 140 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
8. 8.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
9. 9.Which of these saves electricity? (a) switch off empty rooms (b) leave fridge door open (c) run fans in empty rooms (d) use old filament bulbs
10. 10.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) a filament bulb (d) an oil lamp
11. 11.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) set the AC to 24 °C (d) iron one shirt at a time
12. 12.🧾 A 100 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
13. 13.Which of these saves electricity? (a) use old filament bulbs (b) use LED lamps (c) leave the TV on standby (d) run fans in empty rooms
14. 14.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use daylight to read (c) use LED lamps (d) set the AC to 24 °C
15. 15.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
16. 16.🧾 A family uses 180 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
17. 17.🧾 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?
18. 18.True or false: to leave fridge door open saves electricity. (a) True (b) False
19. 19.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
20. 20.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) unplug idle chargers (d) leave the TV on standby
21. 21.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
22. 22.Which of these wastes electricity? (a) leave the TV on standby (b) close the fridge quickly (c) unplug idle chargers (d) use daylight to read
23. 23.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) leave the TV on standby (d) use daylight to read
24. 24.🔍 Which is the odd one out? (a) unplug idle chargers (b) use daylight to read (c) use LED lamps (d) leave the TV on standby
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 2 hours. How many watt-hours (Wh) are saved?
26. 26.Which of these wastes electricity? (a) run fans in empty rooms (b) use LED lamps (c) switch off empty rooms (d) unplug idle chargers
27. 27.🧾 A 2000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
28. 28.True or false: to leave the TV on standby saves electricity. (a) True (b) False
29. 29.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
30. 30.🔍 Which is the odd one out? (a) use daylight to read (b) unplug idle chargers (c) close the fridge quickly (d) run fans in empty rooms
31. 31.True or false: to use daylight to read wastes electricity. (a) False (b) True
32. 32.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
33. 33.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
34. 34.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
35. 35.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
36. 36.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
37. 37.🧾 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?
38. 38.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
39. 39.True or false: to unplug idle chargers saves electricity. (a) False (b) True
40. 40.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =

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