Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 112 · 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 resistor has the colour bands violet, white, black. What is its value (in ohms)?
2. 2.🔢 To plan an electronics project, which comes first: “list inputs and outputs” or “pick a problem to solve”? (a) list inputs and outputs (b) pick a problem to solve
3. 3.🧮 Resistors of 150 Ω, 22 Ω, 20 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
4. 4.🔺 A current of 50 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
5. 5.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
6. 6.🌈 Which band is read first on a resistor? (a) the gold band (b) any band (c) the one nearest an end (d) the widest gap
7. 7.⚙️ What is an actuator? (a) a battery (b) a program (c) an output that acts (d) a sensor
8. 8.🔺 A current of 20 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
9. 9.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 7 HIGH
   set pin 8 HIGH
   set pin 8 HIGH
   set pin 8 HIGH
   Is the LED ON or OFF at the end? (a) ON (b) OFF
10. 10.🔺 A 0.75 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
11. 11.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 18) { show “Warm” } else { show “Cool” }
    The temperature is 25 °C. What is shown? (a) Warm (b) Hot (c) Cool
12. 12.⚠️ Is it safe to use small battery cells? (a) safe (b) not safe
13. 13.True or false: “a tilt switch: on or off” is an analog signal. (a) True (b) False
14. 14.⏱️ A program says “wait 3000 ms”. How many seconds is that? =
15. 15.🧮 Five equal 25 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
16. 16.True or false: many long-short pairs is the symbol for an LED. (a) False (b) True
17. 17.What does a slide switch do? (a) stays where you flip it (b) flips up or down (c) closes near a magnet (d) slides side to side
18. 18.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a copper wire. Does the bulb glow? (a) Yes (b) No
19. 19.🔺 A 6 V supply is joined across a 3 Ω resistor. What current flows (in amperes)? =
20. 20.🌈 A resistor has the colour bands red, violet, black. What is its value (in ohms)?
21. 21.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic straw. Does the bulb glow? (a) No (b) Yes
22. 22.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
23. 23.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) blinks 500 times (d) waits 500 seconds
24. 24.Which of these saves electricity? (a) use old filament bulbs (b) leave the TV on standby (c) unplug idle chargers (d) leave fridge door open
25. 25.🔁 total = 0
    for i = 1 to 11 { total = total + i }
    What is total at the end?
26. 26.Which drawing is the symbol for a capacitor? (a) a circle with an X in it (b) one tall, one short bar (c) two equal parallel lines (d) a line lifted at a gap
27. 27.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 430 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
28. 28.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
29. 29.🧮 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
30. 30.🌈 A resistor has the colour bands violet, black, red. What is its value in kilo-ohms (kΩ)? =
31. 31.What does a reed switch do? (a) closes when tipped over (b) springs back when let go (c) closes near a magnet (d) slides side to side
32. 32.🔋 What is a battery? (a) one single wire (b) two or more cells joined (c) a kind of bulb (d) a switch with a lid
33. 33.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
34. 34.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) when both are OFF (c) when both are ON (d) never
35. 35.🔘 Which kind of switch slides side to side? (a) a push button (b) a slide switch (c) a toggle switch (d) a tilt switch
36. 36.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = R ÷ I (d) V = I × R
37. 37.💡 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?
38. 38.🧾 A 1000 W appliance runs for 5 hours. How many units (kWh) of electricity does it use? =
39. 39.🧩 Which part changes electrical energy into sound? (a) a buzzer (b) a resistor (c) a diode (d) a capacitor
40. 40.True or false: a digital alarm clock has no microcontroller inside. (a) False (b) True

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