Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 9 · 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.Which of these is a risky habit? (a) cover unused cameras (b) share camera links (c) change default passwords (d) set a strong password
2. 2.True or false: a thermistor senses how hot it is. (a) True (b) False
3. 3.🌐 What does IoT stand for? (a) Input of Tools (b) Inside of Toys (c) Internet of Talk (d) Internet of Things
4. 4.💡 3 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
5. 5.What does a reed switch do? (a) springs back when let go (b) works only while pressed (c) closes near a magnet (d) closes when tipped over
6. 6.True or false: if the bulb is unscrewed, the circuit is closed and current flows. (a) False (b) True
7. 7.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V ÷ I (c) P = V + I (d) P = V × I
8. 8.⚡ What do we call a flow of electric charge through a wire? (a) electric current (b) sound (c) friction (d) a magnet
9. 9.Which job is done by the voltage regulator? (a) restarts the program (b) keeps the voltage steady (c) shows the board is on (d) runs the program
10. 10.🔌 Is a rubber band a conductor or an insulator? (a) a conductor (b) an insulator
11. 11.🔺 A current of 2.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
12. 12.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) by Wi-Fi (d) not joined
13. 13.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
14. 14.True or false: on a cell, “the shorter symbol line” means the − (negative) end. (a) True (b) False
15. 15.Which of these is true of a series circuit? (a) used in house wiring (b) each gets the full volts (c) one out, the rest glow (d) a break stops every bulb
16. 16.🔁 count = 3
    while (count < 13) { count = count + 2 }
    How many times does the loop run?
17. 17.🔌 Is a steel coin a conductor or an insulator? (a) a conductor (b) an insulator
18. 18.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) to make bulbs dim (c) so all go off together (d) to save copper only
19. 19.🧮 Two equal 10 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
20. 20.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
21. 21.True or false: a reed switch closes near a magnet. (a) True (b) False
22. 22.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3.5 V supply. What current flows (in mA)?
23. 23.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True
24. 24.💡 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
25. 25.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 3 V supply. What current flows (in mA)?
26. 26.💡 Why does an LED need a resistor in series? (a) to limit the current (b) to change its colour (c) to store charge (d) to make it brighter
27. 27.🔌 Is a brass key a conductor or an insulator? (a) a conductor (b) an insulator
28. 28.⏱️ A program says “wait 750 ms”. How many seconds is that? =
29. 29.True or false: power is measured in ohms (Ω). (a) True (b) False
30. 30.⚙️ What is an actuator? (a) a battery (b) an output that acts (c) a program (d) a sensor
31. 31.🔍 Which is the odd one out? (a) an iron nail (b) a steel spoon (c) a wooden stick (d) a brass key
32. 32.Which of these is measured in volts (V)? (a) resistance (b) current (c) the push of a cell (d) how much a part resists
33. 33.True or false: on an LED, the leg by the flat edge is the anode (+). (a) False (b) True
34. 34.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 3 glow? (a) No (b) Yes
35. 35.🧮 A 470 Ω resistor is joined in series with two equal 220 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
36. 36.⚙️ Which actuator would you use to move water to plants? (a) a buzzer (b) an LED (c) a pump (d) a servo motor
37. 37.🧩 Which component senses how bright it is? (a) thermistor (b) buzzer (c) transistor (d) LDR
38. 38.🔍 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
39. 39.🔁 count = 0
    repeat 8 times { count = count + 6 }
    What is count at the end?
40. 40.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF

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