Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 177 · 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.True or false: “a single current path” is true of a parallel circuit. (a) False (b) True
2. 2.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) True (b) False
3. 3.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
4. 4.🔦 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 wooden stick. Does the bulb glow? (a) No (b) Yes
5. 5.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 7 LOW
   set pin 7 HIGH
   set pin 7 LOW
   set pin 8 HIGH
   set pin 7 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
6. 6.🧮 Resistors of 22 Ω, 50 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
7. 7.💡 3 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
8. 8.🔍 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
9. 9.True or false: a line lifted at a gap is the symbol for a switch. (a) True (b) False
10. 10.🔌 Is a copper wire a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🗺️ Before building a project, what should you write down first? (a) the final price (b) inputs and outputs (c) the box colour (d) nothing at all
13. 13.🔋 7 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
14. 14.🌈 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
15. 15.What does a toggle switch do? (a) works only while pressed (b) springs back when let go (c) flips up or down (d) closes near a magnet
16. 16.True or false: “the room temperature” is a digital signal. (a) True (b) False
17. 17.⏱️ loop forever { LED ON; wait 300 ms; LED OFF; wait 700 ms }
    How many times does the LED blink in 9 seconds?
18. 18.Which of these uses electricity? (a) an air conditioner (b) a generator (c) a solar panel (d) a power station
19. 19.🗺️ In an input → process → output plan, is “a motion sensor signal” the input, the process or the output? (a) input (b) process (c) output
20. 20.🔍 A distance sensor sends a sound pulse and hears the echo 19 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
21. 21.🧾 Which lamp gives the same light for the least power? (a) a candle (b) an LED lamp (c) a filament bulb (d) an oil lamp
22. 22.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in parallel (b) in series (c) by Wi-Fi (d) not joined
23. 23.🔁 What does a variable do in a program? (a) blinks an LED (b) joins two wires (c) stores a value (d) measures light
24. 24.Which job needs a distance sensor? (a) make a parking alarm (b) warn of a gas leak (c) switch on with a clap (d) switch on lamps at dusk
25. 25.📏 Which unit measures energy used each second? (a) ohm (Ω) (b) watt (W) (c) volt (V) (d) ampere (A)
26. 26.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 34 °C. What is shown? (a) Warm (b) Cool (c) Hot
27. 27.🔍 Which is the odd one out? (a) a plastic ruler (b) a safety pin (c) a rubber band (d) a plastic straw
28. 28.🧮 Resistors of 50 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
29. 29.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
30. 30.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
31. 31.🔁 count = 7
    repeat 6 times { count = count + 7 }
    What is count at the end?
32. 32.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 350 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
33. 33.🔍 Which is the odd one out? (a) share camera links (b) reuse one password (c) share only needed data (d) ignore update messages
34. 34.Which of these is true of a parallel circuit? (a) one out, the rest glow (b) one bulb out, all go out (c) a single current path (d) bulbs share the voltage
35. 35.💡 4 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 4 is taken out of its holder. How many bulbs glow?
36. 36.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
37. 37.Which of these means the circuit is open? (a) all wires are joined (b) the switch is ON (c) the loop is complete (d) the switch is OFF
38. 38.💡 What happens if an LED is put in backwards? (a) it makes a sound (b) it lights brighter (c) it changes colour (d) it does not light
39. 39.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put aluminium foil across the gap. Does the bulb glow? (a) No (b) Yes
40. 40.🧩 Which component stores a little charge? (a) buzzer (b) LDR (c) capacitor (d) transistor

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