Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 290 · 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.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
2. 2.🔺 A current of 40 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
3. 3.📶 Digital or analog: a button: pressed or not? (a) analog (b) digital
4. 4.⚙️ Which actuator would you use to turn to an exact angle? (a) a pump (b) a buzzer (c) a servo motor (d) a motor
5. 5.🧮 Resistors of 100 Ω, 10 Ω, 33 Ω and 22 Ω are joined in series. What is the total resistance (in ohms)?
6. 6.🤖 if (temperature > 31) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
   The temperature is 44 °C. What is shown? (a) Cool (b) Warm (c) Hot
7. 7.Which drawing is the symbol for a bulb? (a) a plain rectangle (b) two or more cell symbols (c) a line lifted at a gap (d) a circle with a cross
8. 8.🔐 Which is the strongest password for a home smart camera? (a) 123456 (b) admin (c) password (d) Tiger#Lamp42!Moon
9. 9.What does a toggle switch do? (a) works only while pressed (b) springs back when let go (c) stays where you flip it (d) closes when tipped over
10. 10.🔍 Which sensor would you use to make a parking alarm? (a) a gas sensor (b) a temperature sensor (c) a soil moisture sensor (d) a distance sensor
11. 11.What does a tilt switch do? (a) slides side to side (b) closes when tipped over (c) works only while pressed (d) stays where you flip it
12. 12.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
13. 13.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
14. 14.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
15. 15.🔍 Which sensor would you use to water a dry plant? (a) a sound sensor (b) a soil moisture sensor (c) a distance sensor (d) a light sensor
16. 16.⚡ A device works on 1.5 V and takes 1 A. What is its power (in watts)? =
17. 17.⚠️ Is it safe to open a phone charger? (a) not safe (b) safe
18. 18.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
19. 19.📏 Which unit measures current? (a) ampere (A) (b) volt (V) (c) ohm (Ω) (d) watt (W)
20. 20.🔍 Which is the odd one out? (a) decide if soil is dry (b) the pump turns on (c) count button presses (d) check if temp > 30
21. 21.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) pauses for half a second (c) turns the LED off (d) blinks 500 times
22. 22.⚙️ Which actuator would you use to show the temperature? (a) a motor (b) a display (c) a buzzer (d) an LED
23. 23.🔺 A current of 50 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.Which of these means the circuit is open? (a) the switch is OFF (b) all wires are joined (c) the switch is ON (d) the loop is complete
25. 25.Which drawing is the symbol for a junction? (a) a straight line (b) a dot where wires meet (c) a long and a short line (d) a circle with A inside
26. 26.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to make it brighter (c) to change its colour (d) to store charge
27. 27.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) ammeter (b) voltmeter (c) LED (d) battery
28. 28.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
29. 29.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) stays the same (c) gets smaller (d) gets bigger
30. 30.⚙️ Which actuator would you use to open a gate to 90°? (a) a display (b) a buzzer (c) a servo motor (d) an LED
31. 31.💡 3 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
32. 32.Which of these wastes electricity? (a) use LED lamps (b) run fans in empty rooms (c) use daylight to read (d) switch off empty rooms
33. 33.🤖 How does a new program get onto a microcontroller board? (a) drawn with a pen (b) typed on the chip (c) uploaded over USB (d) sent by sound
34. 34.🔍 Which is the odd one out? (a) a dry cork (b) a woollen thread (c) a copper wire (d) a glass marble
35. 35.🔁 x = 1
    repeat 4 times { x = x × 2 }
    What is x at the end?
36. 36.💡 4 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
37. 37.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
38. 38.True or false: a slide switch closes near a magnet. (a) False (b) True
39. 39.💡 6 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. Does bulb 3 glow? (a) Yes (b) No
40. 40.💡 5 identical bulbs are joined in series with a 20 V battery (ideal wires). How many volts does each bulb get? =

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