Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 494 · 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 resistor has the colour bands orange, violet, orange. What is its value in kilo-ohms (kΩ)? =
2. 2.🔋 Does a generator give electricity or use electricity? (a) gives electricity (b) uses electricity
3. 3.🔺 A current of 25 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
4. 4.🧮 A 10 Ω resistor is joined in series with two equal 200 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
5. 5.📏 How many watts (W) is 0.6 kW?
6. 6.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 2 hours?
7. 7.🔍 Which is the odd one out? (a) leave fridge door open (b) run fans in empty rooms (c) use old filament bulbs (d) set the AC to 24 °C
8. 8.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) turns the LED off (c) waits 500 seconds (d) pauses for half a second
9. 9.True or false: to touch a switch when wet is safe. (a) False (b) True
10. 10.🌈 In the resistor colour code, which number does white stand for?
11. 11.💡 An LED is joined to a 9 V battery through a 1000 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
12. 12.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 253. What happens? (a) lamp OFF (b) lamp ON
13. 13.True or false: many long-short pairs is the symbol for a diode. (a) False (b) True
14. 14.💡 In a series circuit, how many paths does the current have? (a) one (b) none (c) one for each bulb (d) two
15. 15.What does a slide switch do? (a) slides side to side (b) flips up or down (c) works only while pressed (d) closes when tipped over
16. 16.🧭 Which part of a microcontroller board runs the program? (a) the power LED (b) the voltage regulator (c) the USB port (d) the main chip
17. 17.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
18. 18.🌐 In an IoT system, which part stores data online? (a) phone app (b) sensor (c) microcontroller (d) cloud server
19. 19.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
20. 20.🔍 Which sensor would you use to spot someone walking in? (a) a motion sensor (b) a temperature sensor (c) a soil moisture sensor (d) a distance sensor
21. 21.🔘 When a switch is ON, the circuit is … (a) broken (b) cut (c) open (d) closed
22. 22.🧮 Five equal 125 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
23. 23.🤖 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
24. 24.🔁 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
25. 25.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) all wires are joined (d) the bulb is unscrewed
26. 26.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 43 °C. What is shown? (a) Warm (b) Hot (c) Cool
27. 27.🔦 A circuit has a new cell, a good bulb and a switch that is OFF. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
28. 28.Which of these has no microcontroller inside? (a) a smart watch (b) a toy robot (c) a TV remote (d) a spinning top
29. 29.🔍 Which sensor would you use to stop a robot near walls? (a) a distance sensor (b) a rain sensor (c) a light sensor (d) a temperature sensor
30. 30.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 25 % (c) 50 % (d) 0 %
31. 31.🔺 A current of 20 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🔋 8 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
33. 33.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
34. 34.🔋 A 12 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
35. 35.True or false: “a buzzer beeps” is the output. (a) True (b) False
36. 36.💡 An LED is joined to a 9 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) may burn out (b) does not light (c) lights up
37. 37.Which drawing is the symbol for a wire? (a) a small empty box (b) a circle with an X in it (c) one tall, one short bar (d) a straight line
38. 38.🔍 Which is the odd one out? (a) aluminium foil (b) a woollen thread (c) a safety pin (d) a brass key
39. 39.📏 Which unit measures the flow of charge? (a) ohm (Ω) (b) ampere (A) (c) volt (V) (d) watt (W)
40. 40.Which of these is the process? (a) check if temp > 30 (b) the fan starts (c) a motion sensor signal (d) a buzzer beeps

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