Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 630 · 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.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 490 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
2. 2.🔁 total = 0
   for i = 1 to 5 { total = total + i }
   What is total at the end?
3. 3.🌈 A resistor has the colour bands red, black, orange. What is its value in kilo-ohms (kΩ)? =
4. 4.Which of these is measured in volts (V)? (a) the flow of charge (b) the push of a cell (c) current (d) how much a part resists
5. 5.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) adds 1 to count (d) prints 1
6. 6.🔐 Which is the strongest password for a home smart camera? (a) Tiger#Lamp42!Moon (b) admin (c) password (d) 123456
7. 7.🔍 Which is the odd one out? (a) a siren (b) a school bell (c) a loudspeaker (d) an electric drill
8. 8.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
9. 9.Which of these wastes electricity? (a) switch off empty rooms (b) use daylight to read (c) use old filament bulbs (d) close the fridge quickly
10. 10.🔍 Which sensor would you use to close a window in rain? (a) a soil moisture sensor (b) a rain sensor (c) a motion sensor (d) a gas sensor
11. 11.Which of these is an IoT device? (a) a plain wall switch (b) a smart energy meter (c) a battery torch (d) a pencil sharpener
12. 12.True or false: a motor beeps for an alarm. (a) True (b) False
13. 13.🤖 if (light < 500) { lamp ON } else { lamp OFF }
    The light sensor reads 632. What happens? (a) lamp ON (b) lamp OFF
14. 14.What does a push button do? (a) closes when tipped over (b) slides side to side (c) works only while pressed (d) stays where you flip it
15. 15.Which of these means the circuit is open? (a) the switch is ON (b) a cell is taken out (c) the loop is complete (d) all wires are joined
16. 16.🔺 A current of 2.5 A flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
17. 17.🧮 A 47 Ω resistor is joined in series with two equal 20 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
18. 18.🔺 A 6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
19. 19.💡 A red LED uses 2 V and should get 10 mA. It runs from a 12 V supply. What resistor (in ohms) is needed in series?
20. 20.🔐 Is it a good or a risky habit to ignore update messages? (a) good habit (b) risky habit
21. 21.⏱️ How many milliseconds is a wait of 1.2 seconds?
22. 22.💡 3 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
23. 23.True or false: a dot where wires meet is the symbol for a junction. (a) False (b) True
24. 24.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a paper strip across the gap. Does the bulb glow? (a) No (b) Yes
25. 25.🧩 Which component boosts a small signal? (a) potentiometer (b) transistor (c) buzzer (d) capacitor
26. 26.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
27. 27.💡 What happens if an LED is put in backwards? (a) it does not light (b) it lights brighter (c) it changes colour (d) it makes a sound
28. 28.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
29. 29.What does the sensor do? (a) measures the real world (b) carries the data (c) acts on a command (d) reads values, decides
30. 30.True or false: a washing machine usually has a microcontroller inside. (a) False (b) True
31. 31.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) process (b) output (c) input
32. 32.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) all wires are joined (d) the bulb is unscrewed
33. 33.🤖 How does a new program get onto a microcontroller board? (a) uploaded over USB (b) typed on the chip (c) drawn with a pen (d) sent by sound
34. 34.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 30 °C. What happens? (a) fan ON (b) fan OFF
35. 35.⚙️ What is an actuator? (a) a sensor (b) an output that acts (c) a program (d) a battery
36. 36.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is ON, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
37. 37.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 23 °C. What is shown? (a) Hot (b) Warm (c) Cool
38. 38.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
39. 39.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) waits 500 seconds (c) pauses for half a second (d) turns the LED off
40. 40.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =

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