Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 480 · 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.💡 An LED is joined to a 6 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) may burn out (c) does not light
2. 2.True or false: a capacitor turns a fan or wheels. (a) False (b) True
3. 3.True or false: a capacitor senses how hot it is. (a) True (b) False
4. 4.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
5. 5.🔘 A bulb and a cell are joined through 2 switches on 2 side-by-side paths, one switch on each path (parallel). What is the smallest number of switches that must be ON to light the bulb?
6. 6.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
7. 7.Which of these is an IoT device? (a) a battery torch (b) a plain table fan (c) a Wi-Fi weather station (d) a wind-up clock
8. 8.Which drawing is the symbol for a junction? (a) a circle with an X in it (b) a dot where wires meet (c) a small empty box (d) a circle with M inside
9. 9.🔋 Does an air conditioner give electricity or use electricity? (a) gives electricity (b) uses electricity
10. 10.🧩 Which component turns a fan or wheels? (a) motor (b) capacitor (c) buzzer (d) LED
11. 11.🌐 In an IoT system, which part carries the data? (a) sensor (b) actuator (c) Wi-Fi (d) cloud server
12. 12.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a resistor (d) a buzzer
13. 13.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they get dimmer (d) they explode
14. 14.What does a capacitor do? (a) smooths a wobbly supply (b) senses how hot it is (c) makes a beeping sound (d) limits the current
15. 15.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
16. 16.Which of these is the output? (a) a motion sensor signal (b) count button presses (c) a button press (d) a buzzer beeps
17. 17.🧮 Resistors of 100 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
18. 18.🔋 How many 2 V cells must be joined in series to give 8 V?
19. 19.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) electric current (c) friction (d) a magnet
20. 20.Which of these is true of a series circuit? (a) used in house wiring (b) many paths for current (c) one out, the rest glow (d) a single current path
21. 21.📏 Voltmeter or ammeter: which one is joined in series? (a) voltmeter (b) ammeter
22. 22.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
23. 23.True or false: a laptop uses very little power. (a) False (b) True
24. 24.🔌 Is a keypad an input or an output for a microcontroller? (a) input (b) output
25. 25.⏱️ loop forever { LED ON; wait 750 ms; LED OFF; wait 250 ms }
    How many times does the LED blink in 3 seconds?
26. 26.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) more than either one (c) their sum (d) always zero
27. 27.🌈 A resistor has the colour bands red, violet, red. What is its value in kilo-ohms (kΩ)? =
28. 28.📶 On a 5 V board, a pin set HIGH gives about … (a) 230 V (b) 50 V (c) 0 V (d) 5 V
29. 29.Which of these has no microcontroller inside? (a) a bicycle bell (b) a TV remote (c) a digital alarm clock (d) a washing machine
30. 30.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) stores a value (d) joins two wires
31. 31.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a candle (c) a filament bulb (d) an LED lamp
32. 32.Which drawing is the symbol for a resistor? (a) a dot where wires meet (b) two equal parallel lines (c) a small empty box (d) triangle, bar and arrows
33. 33.🔺 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
34. 34.⚡ A home appliance on the 230 V mains takes 1 A. What is its power (in watts)?
35. 35.🔐 Why install updates on IoT devices? (a) they delete the Wi-Fi (b) they make it heavier (c) they change the colour (d) they fix security holes
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 ON. Does the bulb glow? (a) Yes (b) No
37. 37.🔺 A 4 V supply is joined across a 20 Ω resistor. What current flows (in amperes)? =
38. 38.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) No (b) Yes
39. 39.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) + (positive) (b) − (negative)
40. 40.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel

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