Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 161 · 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.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) wire (b) diode (c) battery (d) ammeter
2. 2.Which of these is true of a series circuit? (a) own switch for each bulb (b) a break stops every bulb (c) used in house wiring (d) many paths for current
3. 3.🧾 A 1000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
4. 4.🔺 A 5 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
5. 5.What does a capacitor do? (a) has coloured bands (b) senses how bright it is (c) stores a little charge (d) boosts a small signal
6. 6.⚠️ Which power source should children use for electronics projects? (a) a small battery pack (b) a mains extension board (c) an inverter socket (d) a wall socket
7. 7.Which job is done by the USB port? (a) brings power and code (b) connect sensors and LEDs (c) shows the board is on (d) restarts the program
8. 8.Which of these is the input? (a) decide if soil is dry (b) a button press (c) the fan starts (d) an alert on the phone
9. 9.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) an open circuit (c) a closed circuit (d) a full circuit
10. 10.🔍 Which is the odd one out? (a) a smart energy meter (b) a fitness band with app (c) a paper calendar (d) an app-controlled bulb
11. 11.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) symbols are heavier (c) to make it colourful (d) quick and clear for all
12. 12.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = I ÷ V (d) R = V × I
13. 13.🔺 A 0.6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
14. 14.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) no voltage (d) the same voltage
15. 15.Which of these wastes electricity? (a) unplug idle chargers (b) set the AC to 24 °C (c) close the fridge quickly (d) leave fridge door open
16. 16.🌈 A resistor has the colour bands blue, white, orange. What is its value in kilo-ohms (kΩ)? =
17. 17.🔺 A 9 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
18. 18.⚙️ Which actuator would you use to open a gate to 90°? (a) a servo motor (b) a buzzer (c) a motor (d) a display
19. 19.Which drawing is the symbol for a voltmeter? (a) a line lifted at a gap (b) a long and a short line (c) a plain rectangle (d) a circle with V inside
20. 20.⏱️ How many milliseconds is a wait of 1.5 seconds?
21. 21.📏 Voltmeter or ammeter: which one measures current? (a) voltmeter (b) ammeter
22. 22.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) blinks 500 times (c) waits 500 seconds (d) pauses for half a second
23. 23.🤖 Does a bicycle bell usually have a microcontroller inside? (a) No (b) Yes
24. 24.🔍 Which is the odd one out? (a) touch a switch when wet (b) take cells out after use (c) stop if a part gets hot (d) dry your hands first
25. 25.🔁 count = 2
    while (count < 11) { count = count + 3 }
    How many times does the loop run?
26. 26.True or false: to use mains for a project is not safe. (a) False (b) True
27. 27.🔍 Which is the odd one out? (a) a glass marble (b) a wooden stick (c) a safety pin (d) a ceramic cup
28. 28.💡 5 identical bulbs are joined in parallel across a 12 V battery (ideal wires). How many volts does each bulb get? =
29. 29.🔍 Which is the odd one out? (a) decide if soil is dry (b) compare with a limit (c) check if temp > 30 (d) a light level reading
30. 30.📏 How many ohms (Ω) is 6.5 kΩ?
31. 31.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
32. 32.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) bulbs share the voltage (c) a single current path (d) one out, the rest glow
33. 33.🔍 Which is the odd one out? (a) a water heater (b) an electric kettle (c) an exhaust fan (d) an electric iron
34. 34.🔺 A current of 0.2 A flows when 2 V is joined across a resistor. What is its resistance (in ohms)?
35. 35.⏱️ repeat 2 times { buzzer ON; wait 200 ms; buzzer OFF; wait 400 ms }
    How many milliseconds does this take in all?
36. 36.🔺 A current of 10 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
37. 37.🔐 Why install updates on IoT devices? (a) they change the colour (b) they delete the Wi-Fi (c) they make it heavier (d) they fix security holes
38. 38.Which of these mainly gives out light? (a) an electric drill (b) a toaster (c) a loudspeaker (d) a torch
39. 39.What does the cloud server do? (a) stores data online (b) reads values, decides (c) acts on a command (d) shows data to you
40. 40.Which of these mainly gives out light? (a) a table fan (b) a doorbell (c) a loudspeaker (d) a night lamp

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