Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 658 · 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.🔋 What should you do with used-up cells? (a) cut them open (b) bury them in soil (c) give them for recycling (d) throw them in a fire
2. 2.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) share it with friends (c) ask a parent first (d) post it online
3. 3.Which of these gives us electricity? (a) an air conditioner (b) a cell (c) a refrigerator (d) a television
4. 4.💡 Does it save or waste electricity to set the AC to 24 °C? (a) wastes electricity (b) saves electricity
5. 5.🔍 A distance sensor sends a sound pulse and hears the echo 11 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
6. 6.True or false: a plain rectangle is the symbol for a wire. (a) False (b) True
7. 7.🧩 Which component boosts a small signal? (a) transistor (b) fuse (c) buzzer (d) LDR
8. 8.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 760 Ω resistor? (a) violet-blue-red (b) blue-violet-brown (c) violet-blue-brown (d) violet-blue-black
9. 9.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
10. 10.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
11. 11.True or false: “one bulb out, all go out” is true of a series circuit. (a) False (b) True
12. 12.🔺 A 6 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
13. 13.📏 Voltmeter or ammeter: which one measures voltage? (a) voltmeter (b) ammeter
14. 14.True or false: if a wire has come loose, the circuit is open and no current flows. (a) False (b) True
15. 15.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) not joined (c) in series (d) by Wi-Fi
16. 16.🤖 if (sound > 70) { red LED ON } else { green LED ON }
    The sound sensor reads 58. What happens? (a) red LED ON (b) green LED ON
17. 17.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
18. 18.🔺 A current of 10 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🔌 Is a plastic straw a conductor or an insulator? (a) a conductor (b) an insulator
20. 20.⏱️ repeat 9 times { buzzer ON; wait 1000 ms; buzzer OFF; wait 600 ms }
    How many milliseconds does this take in all?
21. 21.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is ON and D is OFF. Does the bulb glow? (a) No (b) Yes
22. 22.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 5 % (c) 50 % (d) 25 %
23. 23.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 2 and 3 are taken out of their holders. Does bulb 6 glow? (a) No (b) Yes
24. 24.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
25. 25.Which of these mainly gives out light? (a) an exhaust fan (b) a room heater (c) an electric iron (d) an LED lamp
26. 26.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only A is true (c) only B is true (d) both are false
27. 27.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) True (b) False
28. 28.📏 How many ohms (Ω) is 6 kΩ?
29. 29.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
30. 30.What does a fuse do? (a) has coloured bands (b) blows if current is high (c) smooths a wobbly supply (d) boosts a small signal
31. 31.True or false: “check if temp > 30” is the output. (a) True (b) False
32. 32.⚡ Power tells us … (a) the colour of light (b) the size of a cell (c) the length of a wire (d) energy used each second
33. 33.💡 Why is house wiring done in parallel? (a) so all go off together (b) to save copper only (c) each gets full voltage (d) to make bulbs dim
34. 34.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the longer line (c) the shorter line (d) both lines
35. 35.🧾 A 200 W appliance runs for 8 hours. How many units (kWh) of electricity does it use? =
36. 36.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) no voltage (c) the same voltage (d) a smaller voltage
37. 37.🧩 A capacitor in a circuit can … (a) store charge briefly (b) measure heat (c) make light (d) spin a wheel
38. 38.🧮 Resistors of 47 Ω, 50 Ω and 150 Ω are joined in series. What is the total resistance (in ohms)?
39. 39.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
40. 40.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) it deletes itself (c) it starts again (d) the board breaks

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids