Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 232 · 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.📏 How many kilo-ohms (kΩ) is 4100 Ω? =
2. 2.🤖 if (light < 400) { lamp ON } else { lamp OFF }
   The light sensor reads 312. What happens? (a) lamp OFF (b) lamp ON
3. 3.Which of these is the process? (a) check if temp > 30 (b) a buzzer beeps (c) an alert on the phone (d) a motion sensor signal
4. 4.🔍 Which is the odd one out? (a) an electric kettle (b) a rice cooker (c) an electric iron (d) a traffic signal
5. 5.🔺 A current of 2.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
6. 6.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
7. 7.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) it deletes itself (c) the board breaks (d) it starts again
8. 8.🔗 Series or parallel circuit: “each gets the full volts”? (a) series (b) parallel
9. 9.Which of these is the output? (a) a soil moisture reading (b) check if temp > 30 (c) count button presses (d) the pump turns on
10. 10.Which of these is an IoT device? (a) an app-controlled bulb (b) a plain wall switch (c) a plain table fan (d) a wind-up clock
11. 11.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) little stars (c) wavy lines (d) straight lines
12. 12.True or false: a potentiometer is a resistance knob. (a) False (b) True
13. 13.Which of these means the circuit is closed? (a) a cell is taken out (b) a wire is cut (c) the loop is complete (d) the bulb is unscrewed
14. 14.🧾 One “unit” on an electricity bill is … (a) 1 ampere (b) 1 volt (c) 1 kilowatt-hour (kWh) (d) 1 watt
15. 15.📏 Voltmeter or ammeter: which one is joined across a part? (a) ammeter (b) voltmeter
16. 16.🔍 Which is the odd one out? (a) a rubber band (b) aluminium foil (c) a cotton thread (d) a woollen thread
17. 17.Which of these is not safe? (a) stay away from pylons (b) build with an adult near (c) fly kites in open fields (d) climb an electric pole
18. 18.🔍 Which sensor would you use to switch on with a clap? (a) a sound sensor (b) a light sensor (c) a motion sensor (d) a gas sensor
19. 19.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
20. 20.📏 Which unit measures energy used each second? (a) ampere (A) (b) ohm (Ω) (c) watt (W) (d) volt (V)
21. 21.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
22. 22.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
23. 23.What does the cloud server do? (a) stores data online (b) acts on a command (c) reads values, decides (d) measures the real world
24. 24.What does a motor do? (a) lets current go one way (b) makes things spin (c) limits the current (d) smooths a wobbly supply
25. 25.🔌 Is a cotton thread a conductor or an insulator? (a) a conductor (b) an insulator
26. 26.📏 Voltmeter or ammeter: which one measures voltage? (a) ammeter (b) voltmeter
27. 27.💡 6 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
28. 28.Which of these is the process? (a) a motion sensor signal (b) a button press (c) decide if soil is dry (d) the fan starts
29. 29.True or false: how much a part resists is measured in ohms (Ω). (a) True (b) False
30. 30.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 370 Ω resistor? (a) violet-orange-brown (b) orange-violet-red (c) orange-violet-black (d) orange-violet-brown
31. 31.🧮 Two resistors in parallel give a total that is … (a) always zero (b) more than either one (c) their sum (d) less than either one
32. 32.Which job needs a light sensor? (a) spot someone walking in (b) switch on lamps at dusk (c) close a window in rain (d) start a fan when hot
33. 33.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 580 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
34. 34.✏️ In a circuit diagram, which part is drawn as triangle against a bar? (a) diode (b) voltmeter (c) resistor (d) cell
35. 35.🔗 Series or parallel circuit: “bulbs share the voltage”? (a) series (b) parallel
36. 36.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 100 (b) 1024 (c) 10 (d) 1000
37. 37.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False
38. 38.💡 Why does an LED need a resistor in series? (a) to store charge (b) to limit the current (c) to change its colour (d) to make it brighter
39. 39.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) no voltage (c) the same voltage (d) half the voltage
40. 40.True or false: a laptop runs many apps at once. (a) False (b) True

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