Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 35 · 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 lamp gives the same light for the least power? (a) a candle (b) an LED lamp (c) a filament bulb (d) an oil lamp
2. 2.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
3. 3.🧾 A 50 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
4. 4.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
5. 5.💡 Does it save or waste electricity to use old filament bulbs? (a) wastes electricity (b) saves electricity
6. 6.🔍 Which is the odd one out? (a) iron one shirt at a time (b) run fans in empty rooms (c) use daylight to read (d) leave the TV on standby
7. 7.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
8. 8.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
9. 9.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
10. 10.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
11. 11.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
12. 12.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
13. 13.🔍 Which is the odd one out? (a) leave fridge door open (b) set the AC to 24 °C (c) use daylight to read (d) use LED lamps
14. 14.Which of these wastes electricity? (a) close the fridge quickly (b) set the AC to 24 °C (c) use LED lamps (d) leave the TV on standby
15. 15.Which of these wastes electricity? (a) switch off empty rooms (b) use LED lamps (c) close the fridge quickly (d) use old filament bulbs
16. 16.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) leave the TV on standby (d) unplug idle chargers
17. 17.True or false: to iron one shirt at a time saves electricity. (a) True (b) False
18. 18.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 ampere (c) 1 volt (d) 1 kilowatt-hour (kWh)
19. 19.True or false: to leave fridge door open saves electricity. (a) False (b) True
20. 20.Which of these saves electricity? (a) run fans in empty rooms (b) iron one shirt at a time (c) leave the TV on standby (d) close the fridge quickly
21. 21.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
22. 22.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
23. 23.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use daylight to read (c) unplug idle chargers (d) use LED lamps
24. 24.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
25. 25.🔍 Which is the odd one out? (a) iron one shirt at a time (b) unplug idle chargers (c) run fans in empty rooms (d) leave fridge door open
26. 26.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
27. 27.🧾 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?
28. 28.True or false: to use old filament bulbs saves electricity. (a) False (b) True
29. 29.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
30. 30.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
31. 31.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
32. 32.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
33. 33.🧾 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?
34. 34.🧾 A family uses 80 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
35. 35.True or false: to use LED lamps wastes electricity. (a) True (b) False
36. 36.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
37. 37.🔍 Which is the odd one out? (a) set the AC to 24 °C (b) use old filament bulbs (c) leave the TV on standby (d) iron one shirt at a time
38. 38.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
39. 39.🧾 A family uses 50 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
40. 40.True or false: to unplug idle chargers saves electricity. (a) False (b) True

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