Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 667 · 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.🧾 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?
2. 2.True or false: to leave fridge door open wastes electricity. (a) True (b) False
3. 3.🧾 A family uses 140 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
4. 4.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 ampere (c) 1 watt (d) 1 kilowatt-hour (kWh)
5. 5.🧾 A family uses 140 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
6. 6.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
7. 7.Which of these wastes electricity? (a) use old filament bulbs (b) use daylight to read (c) switch off empty rooms (d) use LED lamps
8. 8.🧾 A family uses 200 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
9. 9.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
10. 10.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
11. 11.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
12. 12.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) run fans in empty rooms (d) close the fridge quickly
13. 13.🔍 Which is the odd one out? (a) switch off empty rooms (b) unplug idle chargers (c) leave fridge door open (d) set the AC to 24 °C
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 1 hour. How many watt-hours (Wh) are saved?
15. 15.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) switch off empty rooms (d) leave fridge door open
16. 16.Which of these saves electricity? (a) leave the TV on standby (b) close the fridge quickly (c) iron one shirt at a time (d) leave fridge door open
17. 17.🔍 Which is the odd one out? (a) close the fridge quickly (b) run fans in empty rooms (c) set the AC to 24 °C (d) switch off empty rooms
18. 18.🔍 Which is the odd one out? (a) use old filament bulbs (b) iron one shirt at a time (c) leave the TV on standby (d) unplug idle chargers
19. 19.Which of these wastes electricity? (a) use LED lamps (b) use daylight to read (c) leave fridge door open (d) switch off empty rooms
20. 20.🧾 A family uses 180 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
21. 21.Which of these wastes electricity? (a) use LED lamps (b) use daylight to read (c) leave the TV on standby (d) unplug idle chargers
22. 22.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) iron one shirt at a time (d) set the AC to 24 °C
23. 23.🧾 A 1500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
24. 24.🧾 A family uses 30 units of electricity in a month and each unit costs ₹6. 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 7 hours. How many watt-hours (Wh) are saved?
26. 26.Which of these saves electricity? (a) leave the TV on standby (b) use old filament bulbs (c) leave fridge door open (d) set the AC to 24 °C
27. 27.🧾 A 200 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
28. 28.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
29. 29.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
30. 30.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
31. 31.🧾 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?
32. 32.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use old filament bulbs (c) run fans in empty rooms (d) switch off empty rooms
33. 33.🧾 A family uses 60 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
34. 34.Which of these saves electricity? (a) run fans in empty rooms (b) use old filament bulbs (c) leave the TV on standby (d) use LED lamps
35. 35.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
36. 36.🧾 A 500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
37. 37.🧾 A 1000 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
38. 38.🧾 A family uses 170 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
39. 39.🧾 Which lamp gives the same light for the least power? (a) a candle (b) a filament bulb (c) an oil lamp (d) an LED lamp
40. 40.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity

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