Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 497 · 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.Which of these saves electricity? (a) leave the TV on standby (b) run fans in empty rooms (c) iron one shirt at a time (d) close the fridge quickly
2. 2.🔍 Which is the odd one out? (a) run fans in empty rooms (b) set the AC to 24 °C (c) use old filament bulbs (d) leave the TV on standby
3. 3.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
4. 4.True or false: to set the AC to 24 °C saves electricity. (a) True (b) False
5. 5.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
6. 6.🔍 Which is the odd one out? (a) leave fridge door open (b) use old filament bulbs (c) switch off empty rooms (d) run fans in empty rooms
7. 7.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
8. 8.🧾 A family uses 100 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
9. 9.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) leave the TV on standby (d) use daylight to read
10. 10.🧾 A family uses 20 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
11. 11.🧾 A family uses 50 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
12. 12.🔍 Which is the odd one out? (a) leave fridge door open (b) run fans in empty rooms (c) use LED lamps (d) iron one shirt at a time
13. 13.Which of these wastes electricity? (a) set the AC to 24 °C (b) iron one shirt at a time (c) unplug idle chargers (d) use daylight to read
14. 14.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
15. 15.🧾 A 1500 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
16. 16.Which of these wastes electricity? (a) use old filament bulbs (b) close the fridge quickly (c) unplug idle chargers (d) switch off empty rooms
17. 17.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
18. 18.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) an oil lamp (c) a candle (d) a filament bulb
19. 19.🔍 Which is the odd one out? (a) run fans in empty rooms (b) leave fridge door open (c) iron one shirt at a time (d) close the fridge quickly
20. 20.Which of these wastes electricity? (a) switch off empty rooms (b) leave the TV on standby (c) use daylight to read (d) close the fridge quickly
21. 21.True or false: to leave the TV on standby saves electricity. (a) False (b) True
22. 22.True or false: to switch off empty rooms wastes electricity. (a) True (b) False
23. 23.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
24. 24.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
25. 25.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
26. 26.True or false: to run fans in empty rooms saves electricity. (a) True (b) False
27. 27.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
28. 28.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
29. 29.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
30. 30.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
31. 31.Which of these wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) run fans in empty rooms (d) use daylight to read
32. 32.🔍 Which is the odd one out? (a) leave fridge door open (b) unplug idle chargers (c) use old filament bulbs (d) run fans in empty rooms
33. 33.🧾 A family uses 170 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
34. 34.🧾 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?
35. 35.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
36. 36.🧾 A 500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
37. 37.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
38. 38.🧾 A family uses 190 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
39. 39.🧾 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?
40. 40.🔍 Which is the odd one out? (a) use LED lamps (b) leave fridge door open (c) close the fridge quickly (d) unplug idle chargers

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