Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 651 · 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 blue, red, yellow. What is its value in kilo-ohms (kΩ)? =
2. 2.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a plastic straw across the gap. Does the bulb glow? (a) Yes (b) No
3. 3.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) bigger (d) stay the same
4. 4.🔍 Which is the odd one out? (a) a siren (b) a ceiling fan (c) a mixer grinder (d) a table fan
5. 5.🔍 Which is the odd one out? (a) stop if a part gets hot (b) fly kites in open fields (c) touch a switch when wet (d) build with an adult near
6. 6.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) none (b) only one (c) it does not matter (d) both of them
7. 7.🔺 A 4 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
8. 8.🔁 repeat 2 times { repeat 5 times { beep } }
   How many beeps are there?
9. 9.⚠️ Is it safe to stay away from pylons? (a) not safe (b) safe
10. 10.🔦 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
11. 11.💡 4 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
12. 12.🔍 Which is the odd one out? (a) a glass marble (b) a wooden stick (c) a plastic straw (d) a graphite rod
13. 13.✏️ In a circuit diagram, which part is drawn as a line lifted at a gap? (a) junction (b) switch (c) battery (d) capacitor
14. 14.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
15. 15.🔘 Which kind of switch slides side to side? (a) a reed switch (b) a slide switch (c) a tilt switch (d) a toggle switch
16. 16.🔢 To get a sensor reading onto a phone, which comes first: “the board reads it” or “the cloud stores it”? (a) the cloud stores it (b) the board reads it
17. 17.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
18. 18.🔺 A current of 50 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🔺 A 16.5 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
20. 20.⏱️ repeat 6 times { buzzer ON; wait 300 ms; buzzer OFF; wait 400 ms }
    How many milliseconds does this take in all?
21. 21.🔍 Which is the odd one out? (a) a steel coin (b) a copper wire (c) a plastic ruler (d) a graphite rod
22. 22.🌐 In an IoT system, which part shows data to you? (a) Wi-Fi (b) phone app (c) sensor (d) microcontroller
23. 23.⚡ A 0.3 W device works on 3 V. What current does it take (in amperes)? =
24. 24.🔐 Is it a good or a risky habit to install software updates? (a) risky habit (b) good habit
25. 25.⏱️ A program says “wait 3750 ms”. How many seconds is that? =
26. 26.🤖 Does a toy robot usually have a microcontroller inside? (a) Yes (b) No
27. 27.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
28. 28.⏱️ repeat 2 times { buzzer ON; wait 300 ms; buzzer OFF; wait 800 ms }
    How many milliseconds does this take in all?
29. 29.🔐 Is it a good or a risky habit to reuse one password? (a) risky habit (b) good habit
30. 30.True or false: an LDR makes a beeping sound. (a) True (b) False
31. 31.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
32. 32.🔍 Which is the odd one out? (a) a rubber eraser (b) a dry cork (c) a rubber band (d) an iron nail
33. 33.⚡ A device works on 3 V and takes 0.2 A. What is its power (in watts)? =
34. 34.True or false: a buzzer beeps for an alarm. (a) True (b) False
35. 35.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 10 (c) 100 (d) 60
36. 36.⚠️ Is it safe to fly a kite near wires? (a) safe (b) not safe
37. 37.🔁 count = 5
    repeat 5 times { count = count + 8 }
    What is count at the end?
38. 38.💡 An LED is joined to a 5 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) may burn out (b) lights up (c) does not light
39. 39.True or false: a resistor limits the current. (a) True (b) False
40. 40.🌐 What does IoT stand for? (a) Inside of Toys (b) Internet of Things (c) Input of Tools (d) Internet of Talk

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