Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 48 · 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.🤖 Where does the board keep its program when the power is off? (a) flash memory (b) the resistor (c) the USB cable (d) the power LED
2. 2.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 230 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
3. 3.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
4. 4.🧾 A 2000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
5. 5.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
6. 6.💡 A red LED (it uses 2 V) is joined with a 300 Ω resistor to a 6.5 V supply. What current flows (in mA)?
7. 7.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) smaller (d) bigger
8. 8.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.🧩 Which part changes electrical energy into movement? (a) an LED (b) a resistor (c) a motor (d) a fuse
10. 10.Which of these is an output? (a) a push button (b) a sound sensor (c) a keypad (d) a servo motor
11. 11.🔍 An object is 51 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
12. 12.True or false: a TV remote usually has a microcontroller inside. (a) False (b) True
13. 13.🔁 repeat 3 times { repeat 6 times { beep } }
    How many beeps are there?
14. 14.🔍 Which is the odd one out? (a) a rubber eraser (b) a graphite rod (c) a paper strip (d) a plastic straw
15. 15.🔋 A 12 V battery and three 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
16. 16.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
17. 17.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
18. 18.🔌 Is a plastic straw a conductor or an insulator? (a) a conductor (b) an insulator
19. 19.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in series (c) in parallel (d) by Wi-Fi
20. 20.⏱️ How many milliseconds is a wait of 3.7 seconds?
21. 21.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) process (b) input (c) output
22. 22.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 21) { show “Warm” } else { show “Cool” }
    The temperature is 33 °C. What is shown? (a) Cool (b) Hot (c) Warm
23. 23.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
24. 24.🌈 A resistor has the colour bands violet, violet, red. What is its value (in ohms)?
25. 25.True or false: to start a fan when hot, use a temperature sensor. (a) False (b) True
26. 26.🔢 To plan an electronics project, what comes right after “build it with an adult”? (a) test it and fix it (b) pick a problem to solve (c) draw the circuit diagram (d) list inputs and outputs
27. 27.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) laptop (b) microcontroller
28. 28.🔺 A current of 0.2 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
29. 29.Which of these is the process? (a) a soil moisture reading (b) the pump turns on (c) a buzzer beeps (d) compare with a limit
30. 30.True or false: “how bright a room is” is an analog signal. (a) False (b) True
31. 31.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
32. 32.🧮 Resistors of 22 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
33. 33.⚡ A 0.75 W device works on 1.5 V. What current does it take (in amperes)? =
34. 34.What does a push button do? (a) closes near a magnet (b) flips up or down (c) springs back when let go (d) slides side to side
35. 35.⚡ A device works on 24 V and takes 3 A. What is its power (in watts)? =
36. 36.🌈 Which band is read first on a resistor? (a) any band (b) the one nearest an end (c) the widest gap (d) the gold band
37. 37.True or false: a laptop needs much more power. (a) True (b) False
38. 38.🧮 Four equal 200 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
39. 39.True or false: “a button press” is the process. (a) True (b) False
40. 40.🔍 A distance sensor sends a sound pulse and hears the echo 18 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?

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