Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 442 · 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) switch off empty rooms (b) use old filament bulbs (c) use LED lamps (d) close the fridge quickly
2. 2.Which of these wastes electricity? (a) use daylight to read (b) leave fridge door open (c) set the AC to 24 °C (d) close the fridge quickly
3. 3.True or false: to leave the TV on standby saves electricity. (a) False (b) True
4. 4.True or false: to leave the TV on standby wastes electricity. (a) False (b) True
5. 5.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
6. 6.🧾 A family uses 120 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
7. 7.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
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 4 hours. How many watt-hours (Wh) are saved?
9. 9.Which of these saves electricity? (a) run fans in empty rooms (b) set the AC to 24 °C (c) leave the TV on standby (d) iron one shirt at a time
10. 10.Which of these wastes electricity? (a) set the AC to 24 °C (b) unplug idle chargers (c) iron one shirt at a time (d) switch off empty rooms
11. 11.🧾 A 75 W filament bulb is swapped for a 12 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
12. 12.🧾 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
13. 13.🧾 A family uses 170 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
14. 14.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
15. 15.True or false: to leave fridge door open saves electricity. (a) True (b) False
16. 16.🧾 A 250 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
17. 17.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
18. 18.Which of these wastes electricity? (a) use LED lamps (b) set the AC to 24 °C (c) leave the TV on standby (d) unplug idle chargers
19. 19.🔍 Which is the odd one out? (a) close the fridge quickly (b) unplug idle chargers (c) set the AC to 24 °C (d) iron one shirt at a time
20. 20.🧾 A 200 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
21. 21.🧾 A family uses 180 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
22. 22.🔍 Which is the odd one out? (a) use LED lamps (b) leave the TV on standby (c) use old filament bulbs (d) leave fridge door open
23. 23.🧾 A 200 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
24. 24.True or false: to use old filament bulbs wastes electricity. (a) False (b) True
25. 25.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
26. 26.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
27. 27.💡 Does it save or waste electricity to iron one shirt at a time? (a) wastes electricity (b) saves electricity
28. 28.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) use LED lamps (d) use old filament bulbs
29. 29.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
30. 30.🧾 A 2000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
31. 31.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
32. 32.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 kilowatt-hour (kWh) (c) 1 watt (d) 1 ampere
33. 33.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
34. 34.🧾 A family uses 40 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
35. 35.Which of these saves electricity? (a) use old filament bulbs (b) unplug idle chargers (c) leave the TV on standby (d) iron one shirt at a time
36. 36.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
37. 37.Which of these saves electricity? (a) iron one shirt at a time (b) leave fridge door open (c) run fans in empty rooms (d) switch off empty rooms
38. 38.True or false: to use LED lamps wastes electricity. (a) True (b) False
39. 39.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 10 hours. How many watt-hours (Wh) are saved?
40. 40.🔍 Which is the odd one out? (a) use daylight to read (b) close the fridge quickly (c) set the AC to 24 °C (d) leave the TV on standby

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