Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 950 · 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.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
2. 2.True or false: to leave fridge door open saves electricity. (a) True (b) False
3. 3.🧾 A family uses 70 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
4. 4.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
5. 5.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 6 hours. How many watt-hours (Wh) are saved?
6. 6.🧾 One “unit” on an electricity bill is … (a) 1 volt (b) 1 watt (c) 1 kilowatt-hour (kWh) (d) 1 ampere
7. 7.Which of these saves electricity? (a) run fans in empty rooms (b) leave fridge door open (c) close the fridge quickly (d) leave the TV on standby
8. 8.🧾 A family uses 30 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
9. 9.🔍 Which is the odd one out? (a) leave fridge door open (b) use daylight to read (c) set the AC to 24 °C (d) use LED lamps
10. 10.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) a candle (c) an oil lamp (d) an LED lamp
11. 11.🧾 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?
12. 12.💡 Does it save or waste electricity to run fans in empty rooms? (a) saves electricity (b) wastes electricity
13. 13.True or false: to iron one shirt at a time wastes electricity. (a) True (b) False
14. 14.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
15. 15.🔍 Which is the odd one out? (a) use daylight to read (b) run fans in empty rooms (c) unplug idle chargers (d) switch off empty rooms
16. 16.🔍 Which is the odd one out? (a) iron one shirt at a time (b) use daylight to read (c) leave fridge door open (d) use old filament bulbs
17. 17.🧾 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?
18. 18.True or false: to switch off empty rooms saves electricity. (a) False (b) True
19. 19.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
20. 20.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
21. 21.🔍 Which is the odd one out? (a) iron one shirt at a time (b) leave the TV on standby (c) set the AC to 24 °C (d) use old filament bulbs
22. 22.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
23. 23.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
24. 24.💡 Does it save or waste electricity to switch off empty rooms? (a) wastes electricity (b) saves electricity
25. 25.Which of these wastes electricity? (a) use daylight to read (b) run fans in empty rooms (c) use LED lamps (d) switch off empty rooms
26. 26.💡 Does it save or waste electricity to leave the TV on standby? (a) saves electricity (b) wastes electricity
27. 27.💡 Does it save or waste electricity to use LED lamps? (a) saves electricity (b) wastes electricity
28. 28.🧾 A 2000 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
29. 29.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
30. 30.🧾 A family uses 190 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
31. 31.Which of these wastes electricity? (a) use LED lamps (b) set the AC to 24 °C (c) unplug idle chargers (d) leave the TV on standby
32. 32.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 9 hours. How many watt-hours (Wh) are saved?
33. 33.🧾 A 100 W filament bulb is swapped for a 15 W LED lamp that gives about the same light. Both would run for 1 hour. How many watt-hours (Wh) are saved?
34. 34.Which of these wastes electricity? (a) switch off empty rooms (b) set the AC to 24 °C (c) leave fridge door open (d) close the fridge quickly
35. 35.🧾 A 60 W filament bulb is swapped for a 9 W LED lamp that gives about the same light. Both would run for 2 hours. How many watt-hours (Wh) are saved?
36. 36.Which of these wastes electricity? (a) use daylight to read (b) set the AC to 24 °C (c) use old filament bulbs (d) close the fridge quickly
37. 37.🧾 A 200 W appliance runs for 6 hours. How many units (kWh) of electricity does it use? =
38. 38.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
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 3 hours. How many watt-hours (Wh) are saved?
40. 40.True or false: to use daylight to read saves electricity. (a) True (b) False

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