Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 690 · 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.Which of these is an IoT device? (a) a paper calendar (b) a Wi-Fi smart plug (c) a battery torch (d) a wind-up clock
2. 2.🧩 Which component has coloured bands? (a) LDR (b) resistor (c) capacitor (d) transistor
3. 3.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a Wi-Fi smart plug (c) a fitness band with app (d) a plain wall switch
4. 4.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
5. 5.🧩 Which component smooths a wobbly supply? (a) potentiometer (b) fuse (c) capacitor (d) resistor
6. 6.💡 Does it save or waste electricity to leave fridge door open? (a) wastes electricity (b) saves electricity
7. 7.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V × R (c) I = R ÷ V (d) I = V ÷ R
8. 8.🔺 A current of 50 mA flows when 16.5 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) the switch is OFF (d) the bulb is unscrewed
10. 10.🔢 To plan an electronics project, what comes right after “list inputs and outputs”? (a) test it and fix it (b) draw the circuit diagram (c) pick a problem to solve (d) build it with an adult
11. 11.Which of these is a conductor? (a) a plastic ruler (b) a rubber eraser (c) a graphite rod (d) a wooden stick
12. 12.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) the bulb is unscrewed (d) all wires are joined
13. 13.🌈 A resistor has the colour bands green, violet, black. What is its value (in ohms)?
14. 14.⚙️ Which actuator would you use to show a status light? (a) a servo motor (b) an LED (c) a pump (d) a motor
15. 15.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
16. 16.🧮 A 1.8 V battery is joined to 10 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
17. 17.⏱️ repeat 10 times { buzzer ON; wait 700 ms; buzzer OFF; wait 600 ms }
    How many milliseconds does this take in all?
18. 18.Which of these usually has a microcontroller inside? (a) a bicycle bell (b) a candle (c) a spinning top (d) a toy robot
19. 19.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
20. 20.What does a toggle switch do? (a) closes near a magnet (b) slides side to side (c) springs back when let go (d) flips up or down
21. 21.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
22. 22.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
23. 23.💡 3 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
24. 24.🧮 Two equal 330 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.🧾 A family uses 170 units of electricity in a month and each unit costs ₹6. What is the bill (in ₹)?
26. 26.🔢 To plan an electronics project, which is the FIRST step? (a) build it with an adult (b) draw the circuit diagram (c) test it and fix it (d) pick a problem to solve
27. 27.🧩 Which component glows using little power? (a) buzzer (b) diode (c) LED (d) resistor
28. 28.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
29. 29.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
30. 30.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) by Wi-Fi (c) in series (d) in parallel
31. 31.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
32. 32.🔺 A current of 50 mA flows when 12.5 V is joined across a resistor. What is its resistance (in ohms)?
33. 33.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they explode (b) they get dimmer (c) they keep glowing (d) they all go out
34. 34.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 390 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
35. 35.True or false: a laptop has no screen of its own. (a) True (b) False
36. 36.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the shorter line (c) the longer line (d) both lines
37. 37.⚡ What does a street light mainly change electricity into? (a) heat (b) light (c) sound (d) movement
38. 38.True or false: “decide if soil is dry” is the process. (a) True (b) False
39. 39.🔍 Which is the odd one out? (a) change default passwords (b) accept every permission (c) share the Wi-Fi key (d) share camera links
40. 40.🔁 What must there be for a current to flow? (a) one loose end (b) a complete loop (c) a broken path (d) a plastic gap

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