Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 131 · 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 capacitor in a circuit can … (a) spin a wheel (b) make light (c) measure heat (d) store charge briefly
2. 2.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 7 HIGH
   set pin 8 HIGH
   set pin 7 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
3. 3.What does a fuse do? (a) glows using little power (b) makes a beeping sound (c) blows if current is high (d) limits the current
4. 4.⏱️ How many milliseconds is a wait of 1.1 seconds?
5. 5.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) only one (c) it does not matter (d) none
6. 6.True or false: a loudspeaker mainly gives out light. (a) False (b) True
7. 7.🤖 Does a plain wall switch usually have a microcontroller inside? (a) Yes (b) No
8. 8.🔢 To get a sensor reading onto a phone, which comes first: “it is sent by Wi-Fi” or “the board reads it”? (a) the board reads it (b) it is sent by Wi-Fi
9. 9.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) bigger (c) stay the same (d) zero
10. 10.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.Which of these is an input? (a) a servo motor (b) a buzzer (c) a light sensor (d) a speaker
12. 12.💡 2 identical bulbs are joined in series with a 6 V battery (ideal wires). How many volts does each bulb get? =
13. 13.True or false: to stop if a part gets hot is not safe. (a) True (b) False
14. 14.True or false: “a door: open or shut” is an analog signal. (a) True (b) False
15. 15.True or false: a toggle switch stays where you flip it. (a) False (b) True
16. 16.Which drawing is the symbol for a motor? (a) two equal parallel lines (b) a dot where wires meet (c) triangle against a bar (d) a circle with M inside
17. 17.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
18. 18.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) neither part (c) the if part (d) the else part
19. 19.🔋 How many 1.2 V cells must be joined in series to give 4.8 V?
20. 20.🔺 A current of 0.1 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
21. 21.🔋 Cells joined + to − in a row (series) give … (a) a bigger voltage (b) a smaller voltage (c) the same voltage (d) no voltage
22. 22.True or false: a rubber eraser is an insulator. (a) False (b) True
23. 23.🔁 count = 1
    repeat 7 times { count = count + 4 }
    What is count at the end?
24. 24.True or false: “a motion sensor signal” is the input. (a) True (b) False
25. 25.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) more than either one (d) less than either one
26. 26.🔍 Which is the odd one out? (a) a torch (b) an electric drill (c) a mixer grinder (d) an exhaust fan
27. 27.True or false: if the switch is ON, the circuit is closed and current flows. (a) False (b) True
28. 28.Which job needs a sound sensor? (a) open blinds at sunrise (b) spot someone walking in (c) water a dry plant (d) switch on with a clap
29. 29.🧩 Which component turns a fan or wheels? (a) diode (b) LED (c) motor (d) buzzer
30. 30.⚠️ Is it safe to touch a fallen wire? (a) not safe (b) safe
31. 31.🔍 A distance sensor sends a sound pulse and hears the echo 14 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
32. 32.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
33. 33.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) No (b) Yes
34. 34.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 50 Ω resistor? (a) green-black-brown (b) blue-black-black (c) blue-green-black (d) green-black-black
35. 35.Which of these is a risky habit? (a) install software updates (b) set up with a parent (c) reuse one password (d) turn off unused gadgets
36. 36.⚡ A device works on 5 V and takes 2 A. What is its power (in watts)? =
37. 37.⚡ A 1.25 W device works on 5 V. What current does it take (in amperes)? =
38. 38.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
39. 39.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
40. 40.🔍 Which is the odd one out? (a) a turning knob (b) a keypad (c) a temperature sensor (d) a buzzer

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