Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 300 · 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.⚡ A 10 W device works on 5 V. What current does it take (in amperes)? =
2. 2.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a ceramic cup across the gap. Does the bulb glow? (a) No (b) Yes
3. 3.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 600 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
4. 4.🔋 A 12 V battery and one 1.5 V cell are joined in series, all facing the same way. What is the total voltage (in volts)? =
5. 5.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) parallel (b) series
6. 6.🔁 repeat 3 times { repeat 5 times { beep } }
   How many beeps are there?
7. 7.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. How many bulbs glow?
8. 8.Which of these is an insulator? (a) aluminium foil (b) a graphite rod (c) a metal paper clip (d) a glass marble
9. 9.🔘 Which kind of switch springs back when let go? (a) a push button (b) a reed switch (c) a toggle switch (d) a tilt switch
10. 10.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
11. 11.🧾 A 250 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
12. 12.🔁 Is the circuit closed or open if the bulb is unscrewed? (a) closed (b) open
13. 13.🔍 Which is the odd one out? (a) leave the TV on standby (b) close the fridge quickly (c) run fans in empty rooms (d) iron one shirt at a time
14. 14.🔁 What does a variable do in a program? (a) measures light (b) blinks an LED (c) stores a value (d) joins two wires
15. 15.Which of these is a good habit? (a) tap unknown app links (b) install software updates (c) share camera links (d) share the Wi-Fi key
16. 16.Which of these uses electricity? (a) a battery (b) a solar panel (c) a cell (d) a television
17. 17.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
18. 18.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
19. 19.Which of these saves electricity? (a) use old filament bulbs (b) unplug idle chargers (c) iron one shirt at a time (d) leave fridge door open
20. 20.🔺 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
21. 21.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
22. 22.True or false: to post your live location is a good habit. (a) True (b) False
23. 23.💡 3 identical bulbs are joined in series with a 3 V battery (ideal wires). How many volts does each bulb get? =
24. 24.🌈 A resistor has the colour bands green, blue, orange. What is its value in kilo-ohms (kΩ)? =
25. 25.🌈 In the resistor colour code, which number does grey stand for?
26. 26.💡 4 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
27. 27.Which job is done by the main chip? (a) brings power and code (b) restarts the program (c) runs the program (d) keeps the voltage steady
28. 28.⚙️ What is an actuator? (a) a battery (b) an output that acts (c) a program (d) a sensor
29. 29.🌐 How does a home IoT device usually send its data to the app? (a) by post (b) by shouting (c) through a candle (d) over Wi-Fi
30. 30.🤖 Does a microwave oven usually have a microcontroller inside? (a) Yes (b) No
31. 31.🔋 What should you do with used-up cells? (a) cut them open (b) bury them in soil (c) give them for recycling (d) throw them in a fire
32. 32.Which of these gives us electricity? (a) a wind turbine (b) a television (c) a computer (d) a mobile phone
33. 33.Which job is done by the pins? (a) runs the program (b) brings power and code (c) connect sensors and LEDs (d) shows the board is on
34. 34.🧮 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
35. 35.🌐 In an IoT system, which part acts on a command? (a) actuator (b) cloud server (c) phone app (d) sensor
36. 36.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
37. 37.⏱️ A program says “wait 3000 ms”. How many seconds is that? =
38. 38.Which of these means the circuit is open? (a) the switch is ON (b) the loop is complete (c) a wire is cut (d) all wires are joined
39. 39.🔁 count = 0
    while (count < 12) { count = count + 2 }
    How many times does the loop run?
40. 40.🔺 A 3.75 V supply is joined across a 150 Ω resistor. What current flows (in milliamperes, mA)?

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