Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 897 · 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 longer leg is the anode (+). (a) False (b) True
2. 2.True or false: “own switch for each bulb” is true of a series circuit. (a) True (b) False
3. 3.🔍 Which is the odd one out? (a) a light sensor (b) a servo motor (c) an LED (d) a buzzer
4. 4.📏 How many amperes (A) is 490 mA? =
5. 5.💡 A battery lights 3 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
6. 6.⚙️ Which actuator would you use to show the temperature? (a) a buzzer (b) a display (c) a motor (d) an LED
7. 7.🧩 A capacitor in a circuit can … (a) store charge briefly (b) make light (c) spin a wheel (d) measure heat
8. 8.Which of these is an IoT device? (a) a paper calendar (b) a plain wall switch (c) a Wi-Fi weather station (d) a pencil sharpener
9. 9.Which of these saves electricity? (a) leave fridge door open (b) leave the TV on standby (c) run fans in empty rooms (d) use LED lamps
10. 10.💡 2 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
11. 11.📶 Digital or analog: a door: open or shut? (a) digital (b) analog
12. 12.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 110 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
13. 13.🔍 Which sensor would you use to keep an incubator warm? (a) a distance sensor (b) a soil moisture sensor (c) a gas sensor (d) a temperature sensor
14. 14.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 4 V supply. What current flows (in mA)?
15. 15.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
16. 16.🔘 What does a switch do in a circuit? (a) changes the voltage (b) stores current (c) opens or closes the loop (d) makes electricity
17. 17.⏱️ repeat 7 times { buzzer ON; wait 100 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
18. 18.⚠️ Is it safe to take cells out after use? (a) not safe (b) safe
19. 19.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 9 cm. What happens? (a) buzzer beeps (b) buzzer is silent
20. 20.🤖 Does a smart watch usually have a microcontroller inside? (a) No (b) Yes
21. 21.True or false: aluminium foil is a conductor. (a) False (b) True
22. 22.True or false: two or more cell symbols is the symbol for a bulb. (a) False (b) True
23. 23.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) by Wi-Fi (d) not joined
24. 24.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a safety pin across the gap. Does the bulb glow? (a) No (b) Yes
25. 25.⏱️ repeat 2 times { buzzer ON; wait 700 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
26. 26.Which of these is the input? (a) the fan starts (b) a soil moisture reading (c) decide if soil is dry (d) a buzzer beeps
27. 27.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the longer line (c) the shorter line (d) both lines
28. 28.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) blinks 500 times (c) waits 500 seconds (d) turns the LED off
29. 29.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they keep glowing (d) they get dimmer
30. 30.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) a battery torch (c) a plain table fan (d) a plain wall switch
31. 31.🔐 A smart speaker is always listening for its wake word. What is a sensible habit? (a) let strangers use it (b) mute it when not in use (c) put it in the bathroom (d) tell it your passwords
32. 32.Which drawing is the symbol for a wire? (a) a circle with V inside (b) a straight line (c) a long and a short line (d) triangle, bar and arrows
33. 33.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
34. 34.🔘 Which kind of switch stays where you flip it? (a) a tilt switch (b) a push button (c) a slide switch (d) a toggle switch
35. 35.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) a smaller voltage (c) no voltage (d) a bigger voltage
36. 36.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
37. 37.Which job needs an LED? (a) open a gate to 90° (b) beep an alarm (c) show a status light (d) turn to an exact angle
38. 38.🧩 Which component boosts a small signal? (a) motor (b) diode (c) LED (d) transistor
39. 39.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False
40. 40.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) resistor (b) diode (c) switch (d) bulb

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