Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 534 · 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 job needs a servo motor? (a) show the temperature (b) beep an alarm (c) open a gate to 90° (d) spin a robot’s wheels
2. 2.🔘 What does a switch do in a circuit? (a) makes electricity (b) changes the voltage (c) opens or closes the loop (d) stores current
3. 3.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
   The temperature is 42 °C. What is shown? (a) Cool (b) Hot (c) Warm
4. 4.⚡ A 3 W device works on 12 V. What current does it take (in amperes)? =
5. 5.Which of these is safe? (a) open a phone charger (b) use mains for a project (c) take cells out after use (d) touch a fallen wire
6. 6.💡 4 identical bulbs are joined in parallel across a 9 V battery (ideal wires). How many volts does each bulb get? =
7. 7.🔌 Is a small display an input or an output for a microcontroller? (a) output (b) input
8. 8.Which of these is an IoT device? (a) a plain wall switch (b) a pencil sharpener (c) an app-controlled bulb (d) a plain table fan
9. 9.🔍 Which is the odd one out? (a) a wind-up clock (b) a battery torch (c) a smart energy meter (d) a plain wall switch
10. 10.⚡ What does a room heater mainly change electricity into? (a) sound (b) light (c) movement (d) heat
11. 11.Which of these is measured in ohms (Ω)? (a) current (b) the push of a cell (c) how much a part resists (d) voltage
12. 12.🧭 Which part of a microcontroller board connect sensors and LEDs? (a) the power LED (b) the reset button (c) the pins (d) the main chip
13. 13.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) the widest gap (d) any band
14. 14.True or false: a bicycle bell has no microcontroller inside. (a) True (b) False
15. 15.🧮 Two equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
16. 16.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
17. 17.🔢 To get a sensor reading onto a phone, which comes first: “the app shows it” or “the sensor measures”? (a) the app shows it (b) the sensor measures
18. 18.Which of these is an output? (a) a buzzer (b) a turning knob (c) a push button (d) a temperature sensor
19. 19.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) resistor (b) wire (c) diode (d) voltmeter
20. 20.🔍 Which is the odd one out? (a) a temperature sensor (b) a light sensor (c) a turning knob (d) a motor
21. 21.🧮 Two resistors in parallel give a total that is … (a) less than either one (b) more than either one (c) always zero (d) their sum
22. 22.💡 2 identical bulbs are joined in series with a 4 V battery (ideal wires). How many volts does each bulb get? =
23. 23.⏱️ How many milliseconds is a wait of 0.5 seconds?
24. 24.True or false: “the room temperature” is a digital signal. (a) True (b) False
25. 25.Which of these is not safe? (a) stop if a part gets hot (b) poke things in a socket (c) stay away from pylons (d) keep drinks far away
26. 26.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they all go out (c) they explode (d) they keep glowing
27. 27.🔍 Which is the odd one out? (a) stop if a part gets hot (b) use small battery cells (c) throw cells in a fire (d) fly kites in open fields
28. 28.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
29. 29.🔁 What does a variable do in a program? (a) blinks an LED (b) joins two wires (c) stores a value (d) measures light
30. 30.🔁 count = 0
    while (count < 25) { count = count + 5 }
    How many times does the loop run?
31. 31.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
32. 32.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) neither line (c) the longer line (d) the shorter line
33. 33.Which drawing is the symbol for a wire? (a) two or more cell symbols (b) two equal parallel lines (c) triangle, bar and arrows (d) a straight line
34. 34.⚠️ Which power source should children use for electronics projects? (a) a wall socket (b) a mains extension board (c) a small battery pack (d) an inverter socket
35. 35.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
36. 36.🔁 Is the circuit closed or open if the loop is complete? (a) open (b) closed
37. 37.Which of these is a good habit? (a) reuse one password (b) cover unused cameras (c) tap unknown app links (d) share camera links
38. 38.🔺 A current of 20 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
39. 39.Which job needs a buzzer? (a) open a gate to 90° (b) spin a robot’s wheels (c) move water to plants (d) beep an alarm
40. 40.🧮 A 33 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)?

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