Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 170 · 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 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?
2. 2.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 watt
3. 3.🧾 A family uses 60 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
4. 4.🧾 A 100 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
5. 5.🔍 Which is the odd one out? (a) use daylight to read (b) run fans in empty rooms (c) leave the TV on standby (d) iron one shirt at a time
6. 6.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) an LED lamp (c) a filament bulb (d) a candle
7. 7.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
8. 8.🧾 A family uses 150 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
9. 9.True or false: to run fans in empty rooms wastes electricity. (a) False (b) True
10. 10.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
11. 11.🧾 A 200 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
12. 12.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
13. 13.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
14. 14.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) leave the TV on standby (d) set the AC to 24 °C
15. 15.🔍 Which is the odd one out? (a) iron one shirt at a time (b) switch off empty rooms (c) use old filament bulbs (d) run fans in empty rooms
16. 16.Which of these wastes electricity? (a) set the AC to 24 °C (b) unplug idle chargers (c) leave the TV on standby (d) use LED lamps
17. 17.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
18. 18.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
19. 19.Which of these wastes electricity? (a) use LED lamps (b) set the AC to 24 °C (c) use old filament bulbs (d) close the fridge quickly
20. 20.True or false: to unplug idle chargers saves electricity. (a) False (b) True
21. 21.True or false: to leave fridge door open saves electricity. (a) True (b) False
22. 22.🔍 Which is the odd one out? (a) leave the TV on standby (b) leave fridge door open (c) use old filament bulbs (d) unplug idle chargers
23. 23.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
24. 24.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
25. 25.🧾 A family uses 30 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
26. 26.🔍 Which is the odd one out? (a) switch off empty rooms (b) unplug idle chargers (c) use daylight to read (d) leave the TV on standby
27. 27.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) iron one shirt at a time (d) switch off empty rooms
28. 28.🧾 A family uses 40 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
29. 29.🔍 Which is the odd one out? (a) iron one shirt at a time (b) close the fridge quickly (c) set the AC to 24 °C (d) switch off empty rooms
30. 30.🔍 Which is the odd one out? (a) leave fridge door open (b) use LED lamps (c) unplug idle chargers (d) switch off empty rooms
31. 31.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
32. 32.🧾 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?
33. 33.True or false: to use daylight to read wastes electricity. (a) True (b) False
34. 34.True or false: to close the fridge quickly wastes electricity. (a) False (b) True
35. 35.Which of these wastes electricity? (a) iron one shirt at a time (b) use LED lamps (c) use daylight to read (d) set the AC to 24 °C
36. 36.🧾 A family uses 190 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
37. 37.🧾 A family uses 30 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
38. 38.🧾 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?
39. 39.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
40. 40.🧾 A family uses 40 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?

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