Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 645 · 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) iron one shirt at a time (c) unplug idle chargers (d) leave fridge door open
2. 2.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 7 hours. How many watt-hours (Wh) are saved?
3. 3.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use LED lamps (c) leave the TV on standby (d) run fans in empty rooms
4. 4.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
5. 5.🧾 A family uses 40 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
6. 6.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
7. 7.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 watt (c) 1 volt (d) 1 kilowatt-hour (kWh)
8. 8.🧾 A 50 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
9. 9.🔍 Which is the odd one out? (a) run fans in empty rooms (b) unplug idle chargers (c) leave fridge door open (d) iron one shirt at a time
10. 10.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
11. 11.True or false: to use LED lamps saves electricity. (a) False (b) True
12. 12.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
13. 13.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
14. 14.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
15. 15.True or false: to unplug idle chargers wastes electricity. (a) False (b) True
16. 16.True or false: to close the fridge quickly saves electricity. (a) False (b) True
17. 17.🧾 A family uses 190 units of electricity in a month and each unit costs ₹7. What is the bill (in ₹)?
18. 18.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
19. 19.🔍 Which is the odd one out? (a) leave fridge door open (b) switch off empty rooms (c) use old filament bulbs (d) run fans in empty rooms
20. 20.True or false: to use daylight to read wastes electricity. (a) False (b) True
21. 21.🔍 Which is the odd one out? (a) unplug idle chargers (b) use old filament bulbs (c) close the fridge quickly (d) use daylight to read
22. 22.Which of these wastes electricity? (a) leave fridge door open (b) set the AC to 24 °C (c) close the fridge quickly (d) unplug idle chargers
23. 23.🧾 A 250 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
24. 24.Which of these wastes electricity? (a) unplug idle chargers (b) switch off empty rooms (c) use old filament bulbs (d) set the AC to 24 °C
25. 25.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) use daylight to read (d) iron one shirt at a time
26. 26.🧾 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?
27. 27.True or false: to leave fridge door open wastes electricity. (a) False (b) True
28. 28.Which of these saves electricity? (a) run fans in empty rooms (b) leave the TV on standby (c) iron one shirt at a time (d) close the fridge quickly
29. 29.Which of these saves electricity? (a) iron one shirt at a time (b) run fans in empty rooms (c) leave the TV on standby (d) switch off empty rooms
30. 30.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
31. 31.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
32. 32.Which of these wastes electricity? (a) use LED lamps (b) switch off empty rooms (c) use daylight to read (d) leave the TV on standby
33. 33.🧾 A 50 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
34. 34.Which of these wastes electricity? (a) close the fridge quickly (b) switch off empty rooms (c) use LED lamps (d) run fans in empty rooms
35. 35.🧾 A 500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
36. 36.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
37. 37.🔍 Which is the odd one out? (a) use old filament bulbs (b) run fans in empty rooms (c) leave fridge door open (d) close the fridge quickly
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 5 hours. How many watt-hours (Wh) are saved?
39. 39.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
40. 40.🔍 Which is the odd one out? (a) close the fridge quickly (b) unplug idle chargers (c) set the AC to 24 °C (d) leave the TV on standby

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