Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 312 · 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.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 1000 (c) 100 (d) 10
2. 2.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a wooden stick. Does the bulb glow? (a) No (b) Yes
3. 3.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
4. 4.📶 How many states can a digital pin have? (a) a thousand (b) one (c) ten (d) two
5. 5.🔺 A 6 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?
6. 6.True or false: “decide if soil is dry” is the output. (a) True (b) False
7. 7.🔢 To run one loop of a plant-watering program, which comes first: “read the soil sensor” or “switch the pump on/off”? (a) switch the pump on/off (b) read the soil sensor
8. 8.⚡ Power tells us … (a) the size of a cell (b) energy used each second (c) the colour of light (d) the length of a wire
9. 9.Which of these is a conductor? (a) a wooden stick (b) a rubber band (c) a steel coin (d) a plastic ruler
10. 10.🔁 count = 1
    while (count < 16) { count = count + 5 }
    How many times does the loop run?
11. 11.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 50 ms }
    How many times does the LED blink in 2 seconds?
12. 12.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 67 %. What happens? (a) pump OFF (b) pump ON
13. 13.Which of these is a risky habit? (a) share only needed data (b) reuse one password (c) cover unused cameras (d) read app permissions
14. 14.🤖 if (light < 400) { lamp ON } else { lamp OFF }
    The light sensor reads 514. What happens? (a) lamp ON (b) lamp OFF
15. 15.Which of these means the circuit is closed? (a) a cell is taken out (b) the switch is ON (c) the bulb is unscrewed (d) a wire has come loose
16. 16.🔋 What is a battery? (a) a kind of bulb (b) one single wire (c) a switch with a lid (d) two or more cells joined
17. 17.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 3 is taken out of its holder. Does bulb 1 glow? (a) Yes (b) No
18. 18.⏱️ repeat 7 times { buzzer ON; wait 600 ms; buzzer OFF; wait 300 ms }
    How many milliseconds does this take in all?
19. 19.What does a push button do? (a) closes near a magnet (b) flips up or down (c) slides side to side (d) works only while pressed
20. 20.💡 4 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
21. 21.🔋 2 identical 1.2 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
22. 22.💡 Why is house wiring done in parallel? (a) to save copper only (b) so all go off together (c) to make bulbs dim (d) each gets full voltage
23. 23.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) smaller (c) bigger (d) zero
24. 24.🔍 Which is the odd one out? (a) log out of shared phones (b) share the Wi-Fi key (c) set up with a parent (d) share only needed data
25. 25.🔘 What does a switch do in a circuit? (a) stores current (b) makes electricity (c) opens or closes the loop (d) changes the voltage
26. 26.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
27. 27.🔌 Is a sound sensor an input or an output for a microcontroller? (a) input (b) output
28. 28.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) motor (b) switch (c) LED (d) bulb
29. 29.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 29000 Ω resistor? (a) red-white-red (b) red-white-yellow (c) red-white-orange (d) white-red-orange
30. 30.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) quick and clear for all (d) symbols are heavier
31. 31.🔁 count = 4
    repeat 6 times { count = count + 4 }
    What is count at the end?
32. 32.⚡ A 9 W device works on 9 V. What current does it take (in amperes)? =
33. 33.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the switch is ON (d) the switch is OFF
34. 34.🔐 Is it a good or a risky habit to post your live location? (a) good habit (b) risky habit
35. 35.📏 How many kilo-ohms (kΩ) is 9500 Ω? =
36. 36.🔺 A current of 0.1 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔍 Which is the odd one out? (a) a push button (b) a small display (c) a light sensor (d) a turning knob
38. 38.🔌 Is a dry cork a conductor or an insulator? (a) a conductor (b) an insulator
39. 39.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V + R (d) I = V ÷ R
40. 40.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =

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