Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 546 · 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.🌐 A weather station sends one reading every 15 seconds. How many readings does it send in 8 minutes?
2. 2.True or false: a toggle switch closes near a magnet. (a) False (b) True
3. 3.True or false: a buzzer has coloured bands. (a) True (b) False
4. 4.💡 Does it save or waste electricity to unplug idle chargers? (a) wastes electricity (b) saves electricity
5. 5.What does the phone app do? (a) reads values, decides (b) acts on a command (c) stores data online (d) shows data to you
6. 6.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) a magnet (c) electric current (d) friction
7. 7.True or false: the ammeter measures current. (a) False (b) True
8. 8.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 25 % (c) 5 % (d) 50 %
9. 9.True or false: a plain wall switch usually has a microcontroller inside. (a) False (b) True
10. 10.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) waits 500 seconds (d) blinks 500 times
11. 11.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an output (c) an input (d) a fuse
12. 12.📏 Voltmeter or ammeter: which one is joined in series? (a) voltmeter (b) ammeter
13. 13.🔁 count = 9
    repeat 6 times { count = count + 4 }
    What is count at the end?
14. 14.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
15. 15.🧮 Resistors of 470 Ω, 33 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
16. 16.🔌 Is a servo motor an input or an output for a microcontroller? (a) input (b) output
17. 17.True or false: to change default passwords is a good habit. (a) False (b) True
18. 18.🔋 What is a battery? (a) two or more cells joined (b) one single wire (c) a switch with a lid (d) a kind of bulb
19. 19.🤖 “if (A AND B)” is true when … (a) only B is true (b) both are false (c) both A and B are true (d) only A is true
20. 20.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 100 ms }
    How many milliseconds does one blink (ON + OFF) take?
21. 21.🧮 Five equal 125 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
22. 22.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 580 and motion is not detected (false). What happens? (a) porch lamp OFF (b) porch lamp ON
23. 23.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) all wires are joined (d) a wire is cut
24. 24.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
25. 25.⚡ A device works on 5 V and takes 1.5 A. What is its power (in watts)? =
26. 26.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) gets smaller (c) becomes zero (d) gets bigger
27. 27.🔐 Who should decide which smart devices go in a child’s room? (a) a parent or guardian (b) an online stranger (c) the app’s adverts (d) nobody at all
28. 28.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V ÷ R (c) I = R ÷ V (d) I = V × R
29. 29.🔁 count = 1
    repeat 10 times { count = count + 7 }
    What is count at the end?
30. 30.🔺 A current of 25 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🌐 In an IoT system, which part shows data to you? (a) microcontroller (b) sensor (c) actuator (d) phone app
32. 32.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) takes 1 away (c) prints 1 (d) adds 1 to count
33. 33.🔍 Which is the odd one out? (a) a graphite rod (b) a metal paper clip (c) a steel coin (d) a plastic ruler
34. 34.🔺 A current of 0.1 A flows when 0.2 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.True or false: an LDR smooths a wobbly supply. (a) True (b) False
36. 36.True or false: on an LED, the round-side leg is the cathode (−). (a) True (b) False
37. 37.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
38. 38.⏱️ How many milliseconds is a wait of 4.6 seconds?
39. 39.🔍 Which is the odd one out? (a) a steel spoon (b) a woollen thread (c) a wooden stick (d) a paper strip
40. 40.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False

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