Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 704 · 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 the process? (a) a light level reading (b) count button presses (c) an LED lights up (d) a soil moisture reading
2. 2.🔺 A current of 3 A flows through a 6 Ω resistor. What is the voltage across it (in volts)? =
3. 3.🔍 Which is the odd one out? (a) a copper wire (b) a safety pin (c) a steel spoon (d) a plastic ruler
4. 4.🔍 An object is 119 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
5. 5.Which of these is not safe? (a) use small battery cells (b) stop if a part gets hot (c) use a cable with cuts (d) keep drinks far away
6. 6.🔍 Which is the odd one out? (a) a servo motor (b) a motion sensor (c) an LED (d) a small display
7. 7.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) two (c) one (d) none
8. 8.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) the app shows it (b) it is sent by Wi-Fi (c) the cloud stores it (d) the board reads it
9. 9.🔁 What does a variable do in a program? (a) blinks an LED (b) measures light (c) joins two wires (d) stores a value
10. 10.Which job needs a servo motor? (a) move water to plants (b) show a status light (c) beep an alarm (d) turn to an exact angle
11. 11.🔺 A current of 20 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
12. 12.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) voltmeter (b) resistor (c) LED (d) cell
13. 13.🔺 In the V-I-R triangle, how do we find R? (a) R = I ÷ V (b) R = V × I (c) R = V ÷ I (d) R = V + I
14. 14.💡 5 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
15. 15.What does a slide switch do? (a) closes when tipped over (b) stays where you flip it (c) flips up or down (d) slides side to side
16. 16.🧮 Four equal 80 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
17. 17.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
18. 18.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
19. 19.🌈 A resistor has the colour bands blue, brown, red. What is its value in kilo-ohms (kΩ)? =
20. 20.💡 What happens if an LED is put in backwards? (a) it lights brighter (b) it makes a sound (c) it does not light (d) it changes colour
21. 21.⏱️ A program says “wait 6250 ms”. How many seconds is that? =
22. 22.Which drawing is the symbol for a switch? (a) a straight line (b) many long-short pairs (c) a plain rectangle (d) a line lifted at a gap
23. 23.✏️ In a circuit diagram, which part is drawn as a small empty box? (a) resistor (b) switch (c) battery (d) junction
24. 24.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) wavy lines (d) dotted circles
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) Yes (b) No
26. 26.🧩 Which component limits the current? (a) buzzer (b) diode (c) fuse (d) resistor
27. 27.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) an open circuit (c) a full circuit (d) a series circuit
28. 28.⏱️ How many milliseconds is a wait of 0.8 seconds?
29. 29.🔺 A current of 0.25 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
30. 30.True or false: a laptop has no screen of its own. (a) False (b) True
31. 31.🔁 Is the circuit closed or open if the switch is OFF? (a) open (b) closed
32. 32.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 25 % (d) 5 %
33. 33.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
34. 34.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) the bulb is unscrewed (d) a cell is taken out
35. 35.🔺 A 6 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.True or false: a push button stays where you flip it. (a) True (b) False
37. 37.⚡ Power tells us … (a) the colour of light (b) the length of a wire (c) the size of a cell (d) energy used each second
38. 38.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
39. 39.🔍 Which is the odd one out? (a) a copper wire (b) a brass key (c) a glass marble (d) a steel coin
40. 40.🗺️ In an input → process → output plan, is “a motion sensor signal” the input, the process or the output? (a) output (b) process (c) input

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