Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 198 · 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 unplug idle chargers? (a) saves electricity (b) wastes electricity
2. 2.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) leave the TV on standby (d) switch off empty rooms
3. 3.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
4. 4.💡 Does it save or waste electricity to iron one shirt at a time? (a) saves electricity (b) wastes electricity
5. 5.True or false: to leave fridge door open saves electricity. (a) False (b) True
6. 6.🧾 A family uses 150 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
7. 7.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 ampere
8. 8.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 8 hours. How many watt-hours (Wh) are saved?
9. 9.💡 Does it save or waste electricity to close the fridge quickly? (a) saves electricity (b) wastes electricity
10. 10.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
11. 11.True or false: to leave the TV on standby saves electricity. (a) True (b) False
12. 12.Which of these wastes electricity? (a) use daylight to read (b) leave the TV on standby (c) set the AC to 24 °C (d) close the fridge quickly
13. 13.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
14. 14.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
15. 15.🧾 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?
16. 16.Which of these wastes electricity? (a) set the AC to 24 °C (b) run fans in empty rooms (c) close the fridge quickly (d) unplug idle chargers
17. 17.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
18. 18.True or false: to iron one shirt at a time wastes electricity. (a) False (b) True
19. 19.🧾 A 200 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
20. 20.Which of these wastes electricity? (a) leave fridge door open (b) close the fridge quickly (c) use LED lamps (d) switch off empty rooms
21. 21.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
22. 22.🔍 Which is the odd one out? (a) leave fridge door open (b) close the fridge quickly (c) use old filament bulbs (d) iron one shirt at a time
23. 23.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
24. 24.🧾 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?
25. 25.🔍 Which is the odd one out? (a) unplug idle chargers (b) leave the TV on standby (c) use LED lamps (d) use daylight to read
26. 26.🔍 Which is the odd one out? (a) use LED lamps (b) close the fridge quickly (c) switch off empty rooms (d) leave fridge door open
27. 27.🧾 A 1500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
28. 28.🧾 A family uses 80 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
29. 29.True or false: to unplug idle chargers saves electricity. (a) False (b) True
30. 30.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave the TV on standby (c) run fans in empty rooms (d) switch off empty rooms
31. 31.🧾 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
32. 32.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
33. 33.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
34. 34.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
35. 35.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) close the fridge quickly (d) use old filament bulbs
36. 36.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
37. 37.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
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 6 hours. How many watt-hours (Wh) are saved?
39. 39.True or false: to use daylight to read saves electricity. (a) True (b) False
40. 40.Which of these saves electricity? (a) iron one shirt at a time (b) leave fridge door open (c) use LED lamps (d) use old filament bulbs

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