Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 253 · 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.Which of these is a good habit? (a) share camera links (b) cover unused cameras (c) ignore update messages (d) reuse one password
2. 2.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
   The temperature is 42 °C. What is shown? (a) Cool (b) Warm (c) Hot
3. 3.True or false: a potentiometer smooths a wobbly supply. (a) True (b) False
4. 4.⚡ A home appliance on the 230 V mains takes 2 A. What is its power (in watts)?
5. 5.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
6. 6.📏 How many amperes (A) is 2840 mA? =
7. 7.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) closed (d) open
8. 8.🔍 Which is the odd one out? (a) build with an adult near (b) throw cells in a fire (c) use small battery cells (d) take cells out after use
9. 9.🔺 A 3 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
10. 10.⏱️ loop forever { LED ON; wait 1000 ms; LED OFF; wait 550 ms }
    How many milliseconds does one blink (ON + OFF) take?
11. 11.🔍 Which is the odd one out? (a) use mains for a project (b) stop if a part gets hot (c) build with an adult near (d) dry your hands first
12. 12.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 25 % (d) 5 %
13. 13.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
14. 14.🤖 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
15. 15.📶 How many states can a digital pin have? (a) two (b) ten (c) one (d) a thousand
16. 16.⚡ What does an LED lamp mainly change electricity into? (a) movement (b) light (c) heat (d) sound
17. 17.🔋 Does an air conditioner give electricity or use electricity? (a) uses electricity (b) gives electricity
18. 18.Which of these is a conductor? (a) a graphite rod (b) a plastic straw (c) a dry cork (d) a cotton thread
19. 19.🔍 Which is the odd one out? (a) poke things in a socket (b) stop if a part gets hot (c) fly kites in open fields (d) dry your hands first
20. 20.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
21. 21.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) the board breaks (c) it starts again (d) it stops forever
22. 22.Which job needs a motion sensor? (a) spot someone walking in (b) warn of a gas leak (c) water a dry plant (d) stop a robot near walls
23. 23.⚡ A device works on 6 V and takes 1 A. What is its power (in watts)? =
24. 24.True or false: a dry cork is a conductor. (a) False (b) True
25. 25.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
26. 26.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
27. 27.🧮 Two resistors in parallel give a total that is … (a) more than either one (b) less than either one (c) always zero (d) their sum
28. 28.🌈 In the resistor colour code, which number does grey stand for?
29. 29.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 224. What happens? (a) lamp OFF (b) lamp ON
30. 30.🔗 Series or parallel circuit: “one out, the rest glow”? (a) series (b) parallel
31. 31.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) both parts (d) the else part
32. 32.True or false: an electric iron mainly gives out heat. (a) True (b) False
33. 33.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to save copper only (c) so all go off together (d) to make bulbs dim
34. 34.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a slide switch (c) a toggle switch (d) a tilt switch
35. 35.🗺️ Before building a project, what should you write down first? (a) the box colour (b) inputs and outputs (c) nothing at all (d) the final price
36. 36.🌐 In an IoT system, which part stores data online? (a) microcontroller (b) Wi-Fi (c) sensor (d) cloud server
37. 37.True or false: “a button: pressed or not” is a digital signal. (a) True (b) False
38. 38.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
39. 39.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) No (b) Yes
40. 40.True or false: a laptop runs one small program. (a) False (b) True

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