Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 174 · 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 close the fridge quickly? (a) saves electricity (b) wastes electricity
2. 2.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
3. 3.🔍 Which is the odd one out? (a) use old filament bulbs (b) leave fridge door open (c) unplug idle chargers (d) iron one shirt at a time
4. 4.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an LED lamp (d) an oil lamp
5. 5.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
6. 6.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
7. 7.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
8. 8.True or false: to unplug idle chargers saves electricity. (a) False (b) True
9. 9.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
10. 10.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
11. 11.True or false: to close the fridge quickly saves electricity. (a) True (b) False
12. 12.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 kilowatt-hour (kWh) (d) 1 watt
13. 13.Which of these wastes electricity? (a) close the fridge quickly (b) use LED lamps (c) run fans in empty rooms (d) unplug idle chargers
14. 14.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
15. 15.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
16. 16.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
17. 17.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) switch off empty rooms (d) leave the TV on standby
18. 18.True or false: to leave the TV on standby saves electricity. (a) False (b) True
19. 19.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
20. 20.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use daylight to read (c) switch off empty rooms (d) leave the TV on standby
21. 21.🧾 A family uses 140 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
22. 22.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave fridge door open (c) leave the TV on standby (d) switch off empty rooms
23. 23.🧾 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?
24. 24.🔍 Which is the odd one out? (a) close the fridge quickly (b) run fans in empty rooms (c) use old filament bulbs (d) iron one shirt at a time
25. 25.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) leave the TV on standby (d) use daylight to read
26. 26.🧾 A family uses 160 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
27. 27.True or false: to leave fridge door open saves electricity. (a) True (b) False
28. 28.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
29. 29.🧾 A 250 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
30. 30.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
31. 31.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
32. 32.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
33. 33.True or false: to leave fridge door open wastes electricity. (a) True (b) False
34. 34.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) leave fridge door open (d) close the fridge quickly
35. 35.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
36. 36.🧾 A family uses 150 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
37. 37.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
38. 38.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) use LED lamps (d) run fans in empty rooms
39. 39.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use old filament bulbs (c) leave the TV on standby (d) use daylight to read
40. 40.🧾 A 100 W filament bulb is swapped for a 15 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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