Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 488 · 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.🤖 if (moisture < 30) { pump ON } else { pump OFF }
   The soil moisture sensor reads 13 %. What happens? (a) pump ON (b) pump OFF
2. 2.⚡ A device works on 5 V and takes 0.5 A. What is its power (in watts)? =
3. 3.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 300 ms }
   How many times does the LED blink in 8 seconds?
4. 4.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) in parallel (c) by Wi-Fi (d) not joined
5. 5.🔁 What must there be for a current to flow? (a) a complete loop (b) a broken path (c) a plastic gap (d) one loose end
6. 6.🧮 Two resistors in parallel give a total that is … (a) their sum (b) less than either one (c) always zero (d) more than either one
7. 7.🔌 Is a plastic straw a conductor or an insulator? (a) an insulator (b) a conductor
8. 8.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
9. 9.Which of these is safe? (a) keep drinks far away (b) use a cable with cuts (c) use mains for a project (d) open a phone charger
10. 10.⏱️ How many milliseconds is a wait of 1.3 seconds?
11. 11.🔺 A current of 25 mA flows when 10 V is joined across a resistor. What is its resistance (in ohms)?
12. 12.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 200 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
13. 13.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
14. 14.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) False (b) True
15. 15.Which drawing is the symbol for a voltmeter? (a) one tall, one short bar (b) a circle with an X in it (c) a circle with V inside (d) a circle with A inside
16. 16.🔦 A circuit has a used-up (dead) 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 graphite rod. Does the bulb glow? (a) Yes (b) No
17. 17.🌈 In the resistor colour code, which number does red stand for?
18. 18.🔌 Is a buzzer an input or an output for a microcontroller? (a) output (b) input
19. 19.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) a cell is taken out (d) the switch is ON
20. 20.🌐 Is a Wi-Fi smart plug an IoT device? (a) not an IoT device (b) an IoT device
21. 21.🔋 What is a battery? (a) a switch with a lid (b) a kind of bulb (c) two or more cells joined (d) one single wire
22. 22.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) takes 1 away (d) adds 1 to count
23. 23.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 35 %. What happens? (a) pump ON (b) pump OFF
24. 24.🌈 A resistor has the colour bands brown, red, orange. What is its value in kilo-ohms (kΩ)? =
25. 25.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
26. 26.🌈 In the resistor colour code, which number does green stand for?
27. 27.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it makes a sound (c) it changes colour (d) it does not light
28. 28.⚠️ Is it safe to stay away from pylons? (a) safe (b) not safe
29. 29.💡 5 identical bulbs are in parallel and each bulb has its own switch on its path. 1 of the switches is OFF and the rest are ON. How many bulbs glow?
30. 30.True or false: a potentiometer is a resistance knob. (a) True (b) False
31. 31.🧮 A 22 Ω resistor is joined in series with two equal 330 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
32. 32.True or false: if the switch is OFF, the circuit is open and no current flows. (a) False (b) True
33. 33.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 0 % (c) 25 % (d) 50 %
34. 34.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
35. 35.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) battery (b) capacitor (c) ammeter (d) cell
36. 36.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) turns the LED off (c) blinks 500 times (d) pauses for half a second
37. 37.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 520 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
38. 38.📏 How many amperes (A) is 1330 mA? =
39. 39.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
40. 40.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF

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