Electronics Worksheet: Electricity Units

Electronics lesson 19: Electricity units and saving power · Set 148 · 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 is the odd one out? (a) set the AC to 24 °C (b) leave the TV on standby (c) switch off empty rooms (d) unplug idle chargers
2. 2.🔍 Which is the odd one out? (a) use old filament bulbs (b) iron one shirt at a time (c) leave fridge door open (d) close the fridge quickly
3. 3.💡 Does it save or waste electricity to leave the TV on standby? (a) wastes electricity (b) saves electricity
4. 4.True or false: to unplug idle chargers wastes electricity. (a) True (b) False
5. 5.🧾 A 1500 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
6. 6.🧾 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?
7. 7.🧾 One “unit” on an electricity bill is … (a) 1 watt (b) 1 kilowatt-hour (kWh) (c) 1 volt (d) 1 ampere
8. 8.🧾 A 100 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
9. 9.🧾 A 1500 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
10. 10.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
11. 11.Which of these saves electricity? (a) leave fridge door open (b) close the fridge quickly (c) run fans in empty rooms (d) leave the TV on standby
12. 12.🧾 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?
13. 13.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
14. 14.💡 Does it save or waste electricity to switch off empty rooms? (a) saves electricity (b) wastes electricity
15. 15.True or false: to close the fridge quickly saves electricity. (a) True (b) False
16. 16.🧾 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
17. 17.🧾 A 50 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
18. 18.🧾 A family uses 190 units of electricity in a month and each unit costs ₹4. What is the bill (in ₹)?
19. 19.🧾 A family uses 80 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
20. 20.🧾 A 250 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
21. 21.🔍 Which is the odd one out? (a) iron one shirt at a time (b) close the fridge quickly (c) set the AC to 24 °C (d) switch off empty rooms
22. 22.🧾 A 100 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
23. 23.🧾 A 1000 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
24. 24.Which of these wastes electricity? (a) close the fridge quickly (b) run fans in empty rooms (c) unplug idle chargers (d) switch off empty rooms
25. 25.🧾 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?
26. 26.True or false: to set the AC to 24 °C saves electricity. (a) False (b) True
27. 27.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
28. 28.True or false: to use LED lamps saves electricity. (a) False (b) True
29. 29.💡 Does it save or waste electricity to close the fridge quickly? (a) wastes electricity (b) saves electricity
30. 30.Which of these saves electricity? (a) use old filament bulbs (b) leave fridge door open (c) switch off empty rooms (d) run fans in empty rooms
31. 31.🧾 A 50 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
32. 32.Which of these saves electricity? (a) use old filament bulbs (b) run fans in empty rooms (c) iron one shirt at a time (d) set the AC to 24 °C
33. 33.Which of these wastes electricity? (a) leave the TV on standby (b) set the AC to 24 °C (c) unplug idle chargers (d) close the fridge quickly
34. 34.True or false: to switch off empty rooms wastes electricity. (a) False (b) True
35. 35.Which of these saves electricity? (a) leave the TV on standby (b) iron one shirt at a time (c) unplug idle chargers (d) use old filament bulbs
36. 36.🧾 A family uses 50 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
37. 37.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
38. 38.💡 Does it save or waste electricity to use LED lamps? (a) wastes electricity (b) saves electricity
39. 39.🧾 A 100 W appliance runs for 4 hours. How many units (kWh) of electricity does it use? =
40. 40.True or false: to use daylight to read saves electricity. (a) True (b) False

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