Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 330 · 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 wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) leave the TV on standby (d) set the AC to 24 °C
2. 2.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
3. 3.True or false: to close the fridge quickly saves electricity. (a) False (b) True
4. 4.True or false: to use LED lamps wastes electricity. (a) True (b) False
5. 5.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
6. 6.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
7. 7.Which of these saves electricity? (a) leave fridge door open (b) use old filament bulbs (c) iron one shirt at a time (d) switch off empty rooms
8. 8.True or false: to leave fridge door open wastes electricity. (a) False (b) True
9. 9.🔍 Which is the odd one out? (a) switch off empty rooms (b) run fans in empty rooms (c) use LED lamps (d) set the AC to 24 °C
10. 10.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 5 hours. How many watt-hours (Wh) are saved?
11. 11.True or false: to set the AC to 24 °C wastes electricity. (a) True (b) False
12. 12.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 ampere
13. 13.Which of these saves electricity? (a) leave the TV on standby (b) leave fridge door open (c) unplug idle chargers (d) use old filament bulbs
14. 14.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
15. 15.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
16. 16.True or false: to unplug idle chargers saves electricity. (a) False (b) True
17. 17.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
18. 18.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
19. 19.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
20. 20.True or false: to run fans in empty rooms saves electricity. (a) False (b) True
21. 21.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
22. 22.🧾 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?
23. 23.Which of these wastes electricity? (a) run fans in empty rooms (b) close the fridge quickly (c) unplug idle chargers (d) set the AC to 24 °C
24. 24.🔍 Which is the odd one out? (a) use LED lamps (b) run fans in empty rooms (c) leave fridge door open (d) iron one shirt at a time
25. 25.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 3 hours. How many watt-hours (Wh) are saved?
26. 26.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
27. 27.🔍 Which is the odd one out? (a) leave fridge door open (b) set the AC to 24 °C (c) unplug idle chargers (d) close the fridge quickly
28. 28.🧾 A 2000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
29. 29.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
30. 30.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
31. 31.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
32. 32.🧾 A family uses 190 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
33. 33.🧾 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
34. 34.🧾 A 60 W filament bulb is swapped for a 9 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 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
36. 36.💡 Does it save or waste electricity to use daylight to read? (a) wastes electricity (b) saves electricity
37. 37.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
38. 38.🧾 A 1500 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
39. 39.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
40. 40.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity

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