Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 145 · 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.🧮 Resistors of 470 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
2. 2.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
3. 3.Which job needs a motor? (a) show a status light (b) move water to plants (c) show the temperature (d) spin a robot’s wheels
4. 4.What does the microcontroller do? (a) acts on a command (b) carries the data (c) measures the real world (d) reads values, decides
5. 5.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 5 % (c) 0 % (d) 25 %
6. 6.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 77 Ω resistor? (a) violet-violet-brown (b) grey-violet-black (c) violet-grey-black (d) violet-violet-black
7. 7.True or false: a microcontroller runs many apps at once. (a) False (b) True
8. 8.💡 Why is house wiring done in parallel? (a) to save copper only (b) to make bulbs dim (c) so all go off together (d) each gets full voltage
9. 9.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
10. 10.🔘 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 OFF, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
11. 11.True or false: a push button works only while pressed. (a) False (b) True
12. 12.Which job needs a gas sensor? (a) switch on with a clap (b) start a fan when hot (c) warn of a gas leak (d) measure classroom noise
13. 13.🔍 Which is the odd one out? (a) a push button (b) a light sensor (c) a turning knob (d) a water pump
14. 14.🔢 To plan an electronics project, which comes first: “build it with an adult” or “list inputs and outputs”? (a) build it with an adult (b) list inputs and outputs
15. 15.Which of these mainly makes sound? (a) a water heater (b) an exhaust fan (c) a rice cooker (d) a buzzer
16. 16.What does a slide switch do? (a) closes when tipped over (b) slides side to side (c) stays where you flip it (d) closes near a magnet
17. 17.📏 How many amperes (A) is 1240 mA? =
18. 18.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
19. 19.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a metal paper clip across the gap. Does the bulb glow? (a) Yes (b) No
20. 20.🔘 Which kind of switch springs back when let go? (a) a toggle switch (b) a slide switch (c) a push button (d) a reed switch
21. 21.🔁 count = 2
    repeat 8 times { count = count + 2 }
    What is count at the end?
22. 22.True or false: a dry cork is an insulator. (a) True (b) False
23. 23.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) the if part (d) both parts
24. 24.Which of these is a conductor? (a) a rubber band (b) a plastic ruler (c) a brass key (d) a wooden stick
25. 25.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 290 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
26. 26.🔋 On a cell, does “the flat end” mean the + end or the − end? (a) + (positive) (b) − (negative)
27. 27.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
28. 28.📏 Which unit measures power? (a) watt (W) (b) volt (V) (c) ampere (A) (d) ohm (Ω)
29. 29.🔢 To get a sensor reading onto a phone, which comes first: “it is sent by Wi-Fi” or “the sensor measures”? (a) it is sent by Wi-Fi (b) the sensor measures
30. 30.⏱️ A program says “wait 9750 ms”. How many seconds is that? =
31. 31.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) waits 500 seconds (c) turns the LED off (d) pauses for half a second
32. 32.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the switch is OFF
33. 33.💡 A blue LED uses 3 V and should get 20 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
34. 34.🌐 In an IoT system, which part shows data to you? (a) Wi-Fi (b) actuator (c) cloud server (d) phone app
35. 35.True or false: a potentiometer blows if current is high. (a) True (b) False
36. 36.🔍 Which is the odd one out? (a) stop if a part gets hot (b) build with an adult near (c) take cells out after use (d) climb an electric pole
37. 37.True or false: a motor makes a beeping sound. (a) False (b) True
38. 38.What does a capacitor do? (a) has coloured bands (b) makes things spin (c) stores a little charge (d) glows using little power
39. 39.Which job is done by the main chip? (a) brings power and code (b) keeps the voltage steady (c) shows the board is on (d) runs the program
40. 40.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)

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