Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 467 · 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.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
2. 2.🔍 Which is the odd one out? (a) tap unknown app links (b) post your live location (c) cover unused cameras (d) keep factory passwords
3. 3.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
4. 4.True or false: a long and a short line is the symbol for a voltmeter. (a) True (b) False
5. 5.True or false: a fuse smooths a wobbly supply. (a) True (b) False
6. 6.🧩 Which component smooths a wobbly supply? (a) capacitor (b) fuse (c) resistor (d) buzzer
7. 7.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) any band (d) the widest gap
8. 8.What does a resistor do? (a) blows if current is high (b) makes things spin (c) has coloured bands (d) turns a fan or wheels
9. 9.🌐 In an IoT system, which part measures the real world? (a) phone app (b) microcontroller (c) actuator (d) sensor
10. 10.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) energy used each second (d) the length of a wire
11. 11.🌈 A resistor has the colour bands orange, green, red. What is its value (in ohms)?
12. 12.🔍 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
13. 13.⚡ A 48 W device works on 24 V. What current does it take (in amperes)? =
14. 14.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) post it online (b) type it all in (c) ask a parent first (d) share it with friends
15. 15.⚡ A device works on 12 V and takes 0.2 A. What is its power (in watts)? =
16. 16.🔍 Which is the odd one out? (a) a fitness band with app (b) a wind-up clock (c) a battery torch (d) a plain wall switch
17. 17.🔺 A current of 0.2 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. A gap in one wire is bridged by an iron nail. Does the bulb glow? (a) No (b) Yes
19. 19.🔍 Which is the odd one out? (a) check if temp > 30 (b) a button press (c) count button presses (d) decide if soil is dry
20. 20.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 10 (b) 1024 (c) 1000 (d) 100
21. 21.🧩 Which part changes electrical energy into sound? (a) a resistor (b) a diode (c) a capacitor (d) a buzzer
22. 22.Which of these is a conductor? (a) a rubber eraser (b) a rubber band (c) a woollen thread (d) a copper wire
23. 23.Which drawing is the symbol for a capacitor? (a) one tall, one short bar (b) a straight line (c) triangle, bar and arrows (d) two equal parallel lines
24. 24.🤖 “if (A AND B)” is true when … (a) only B is true (b) both A and B are true (c) both are false (d) only A is true
25. 25.⚡ Which tiny particles drift along a metal wire to carry the current? (a) photons (b) dust particles (c) water drops (d) electrons
26. 26.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
27. 27.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I ÷ R (d) V = I × R
28. 28.What does a diode do? (a) boosts a small signal (b) lets current go one way (c) turns a fan or wheels (d) glows using little power
29. 29.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 5 V supply. What current flows (in mA)?
30. 30.🔍 Which is the odd one out? (a) a water pump (b) a sound sensor (c) a motion sensor (d) a temperature sensor
31. 31.True or false: a cotton thread is an insulator. (a) True (b) False
32. 32.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic ruler across the gap. Does the bulb glow? (a) Yes (b) No
33. 33.⏱️ repeat 4 times { buzzer ON; wait 500 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
34. 34.🔍 Which is the odd one out? (a) an app-controlled bulb (b) a plain table fan (c) a battery torch (d) a pencil sharpener
35. 35.🔁 count = 1
    repeat 9 times { count = count + 7 }
    What is count at the end?
36. 36.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they explode (c) they get dimmer (d) they all go out
37. 37.🔺 A current of 1 A flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
38. 38.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) watt (W) (c) volt (V) (d) ampere (A)
39. 39.Which job needs a sound sensor? (a) make a parking alarm (b) open blinds at sunrise (c) spot someone walking in (d) switch on with a clap
40. 40.🧾 A family uses 20 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?

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