Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 815 · 40 questions

Remember (Find the topic, use the idea): Find the topic: circuit, safety, formula, component, program, sensor or IoT. Use that lesson’s rule — complete loop, V = I × R, P = V × I, last command wins, true → if part. Safety answers are always: low voltage, dry hands, an adult, never the mains.

1. 1.🧮 A 3.2 V battery is joined to 12 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
2. 2.🧾 A family uses 130 units of electricity in a month and each unit costs ₹9. What is the bill (in ₹)?
3. 3.🔢 To get a sensor reading onto a phone, which comes first: “the cloud stores it” or “the sensor measures”? (a) the cloud stores it (b) the sensor measures
4. 4.🔁 total = 0
   for i = 1 to 11 { total = total + i }
   What is total at the end?
5. 5.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) resistor (c) voltmeter (d) ammeter
6. 6.🔍 Which is the odd one out? (a) a metal paper clip (b) a graphite rod (c) a paper strip (d) a steel spoon
7. 7.True or false: a TV remote has no microcontroller inside. (a) False (b) True
8. 8.🌐 Is a Wi-Fi smart plug an IoT device? (a) not an IoT device (b) an IoT device
9. 9.Which of these means the circuit is open? (a) a wire is cut (b) the switch is ON (c) the loop is complete (d) all wires are joined
10. 10.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 6.5 V supply. What current flows (in mA)?
11. 11.🔍 Which is the odd one out? (a) a buzzer (b) a water pump (c) a speaker (d) a temperature sensor
12. 12.📏 In the water-pipe picture of a circuit, voltage is like … (a) the tap handle (b) the water tank lid (c) the water pressure (d) the pipe colour
13. 13.🔺 A 1.5 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
14. 14.True or false: to switch on with a clap, use a soil moisture sensor. (a) False (b) True
15. 15.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) to make bulbs dim (d) so all go off together
16. 16.💡 An LED is joined to a 9 V battery through a 220 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) does not light (c) lights up
17. 17.True or false: on an LED, the leg by the flat edge is the anode (+). (a) True (b) False
18. 18.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the battery (b) the process (c) the input (d) the output
19. 19.⚠️ Who should be with you when you build a circuit? (a) a younger child (b) a stranger online (c) nobody (d) a trusted adult
20. 20.True or false: to throw cells in a fire is not safe. (a) False (b) True
21. 21.True or false: “a single current path” is true of a series circuit. (a) False (b) True
22. 22.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 510 Ω resistor? (a) brown-green-brown (b) green-brown-red (c) green-brown-black (d) green-brown-brown
23. 23.🔺 A current of 20 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
24. 24.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
25. 25.True or false: “many paths for current” is true of a series circuit. (a) True (b) False
26. 26.🌈 A resistor has the colour bands brown, violet, black. What is its value (in ohms)?
27. 27.🔍 Which is the odd one out? (a) an iron nail (b) a steel coin (c) a dry cork (d) a steel spoon
28. 28.🧾 A 40 W filament bulb is swapped for a 6 W LED lamp that gives about the same light. Both would run for 4 hours. How many watt-hours (Wh) are saved?
29. 29.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is ON, B is OFF, C is OFF and D is OFF. Does the bulb glow? (a) Yes (b) No
30. 30.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 78000 Ω resistor? (a) grey-violet-orange (b) violet-grey-yellow (c) violet-grey-orange (d) violet-grey-red
31. 31.Which of these is measured in watts (W)? (a) how much a part resists (b) voltage (c) power (d) the flow of charge
32. 32.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 12 V (c) 1.5 V (d) 9 V
33. 33.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 500 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
34. 34.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
35. 35.🔍 Which is the odd one out? (a) fly kites in open fields (b) use small battery cells (c) keep drinks far away (d) use mains for a project
36. 36.🔁 count = 1
    repeat 8 times { count = count + 8 }
    What is count at the end?
37. 37.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) dimmer (c) the same
38. 38.🔍 Which is the odd one out? (a) a rubber band (b) a paper strip (c) a wooden stick (d) a metal paper clip
39. 39.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V × I (c) P = V + I (d) P = I ÷ V
40. 40.🔺 A 10 V supply is joined across a 250 Ω resistor. What current flows (in milliamperes, mA)?

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