Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 821 · 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.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
2. 2.Which of these means the circuit is open? (a) all wires are joined (b) the loop is complete (c) the bulb is unscrewed (d) the switch is ON
3. 3.True or false: a brass key is an insulator. (a) True (b) False
4. 4.True or false: the voltmeter measures current. (a) True (b) False
5. 5.True or false: “many paths for current” is true of a parallel circuit. (a) False (b) True
6. 6.🔦 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 aluminium foil. Does the bulb glow? (a) No (b) Yes
7. 7.🧩 Which component glows using little power? (a) resistor (b) LED (c) buzzer (d) potentiometer
8. 8.🔍 Which sensor would you use to close a window in rain? (a) a light sensor (b) a temperature sensor (c) a gas sensor (d) a rain sensor
9. 9.Which of these means the circuit is closed? (a) the switch is ON (b) a wire is cut (c) a cell is taken out (d) a wire has come loose
10. 10.🔁 count = 1
    while (count < 7) { count = count + 2 }
    How many times does the loop run?
11. 11.🔁 What does “count = count + 1” do? (a) adds 1 to count (b) sets count to 1 (c) takes 1 away (d) prints 1
12. 12.True or false: to spot someone walking in, use a temperature sensor. (a) False (b) True
13. 13.🔍 Which sensor would you use to switch on with a clap? (a) a gas sensor (b) a sound sensor (c) a distance sensor (d) a soil moisture sensor
14. 14.🤖 “if (A AND B)” is true when … (a) both are false (b) only A is true (c) only B is true (d) both A and B are true
15. 15.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when either is ON (c) never (d) when both are ON
16. 16.⚠️ Is it safe to stop if a part gets hot? (a) safe (b) not safe
17. 17.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 13 °C. What is shown? (a) Hot (b) Cool (c) Warm
18. 18.🤖 Which is a safe power source for a beginner microcontroller board? (a) USB or a 9 V battery (b) bare mains wires (c) a 230 V cable (d) a wall socket directly
19. 19.📏 How many milliamperes (mA) is 0.63 A?
20. 20.Which of these has no microcontroller inside? (a) a smart watch (b) a spinning top (c) a toy robot (d) a digital alarm clock
21. 21.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) an open circuit (b) a safe circuit (c) a parallel circuit (d) a short circuit
22. 22.🔺 A current of 2 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
23. 23.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 100 (c) 1000 (d) 10
24. 24.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) junction (b) resistor (c) LED (d) switch
25. 25.⚡ What do we call a flow of electric charge through a wire? (a) sound (b) a magnet (c) friction (d) electric current
26. 26.🔌 Is a keypad an input or an output for a microcontroller? (a) output (b) input
27. 27.🔍 Which is the odd one out? (a) set up with a parent (b) turn off unused gadgets (c) share camera links (d) share only needed data
28. 28.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a graphite rod. Does the bulb glow? (a) No (b) Yes
29. 29.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
30. 30.True or false: a steel coin is an insulator. (a) False (b) True
31. 31.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
32. 32.⏱️ repeat 5 times { buzzer ON; wait 800 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
33. 33.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
34. 34.📶 Digital or analog: how loud a sound is? (a) digital (b) analog
35. 35.🔺 A 10 V supply is joined across a 500 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.💡 In a series circuit, how many paths does the current have? (a) none (b) one (c) one for each bulb (d) two
37. 37.🔁 x = 4
    repeat 1 time { x = x × 2 }
    What is x at the end?
38. 38.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
39. 39.🔍 Which is the odd one out? (a) ignore update messages (b) share the Wi-Fi key (c) reuse one password (d) log out of shared phones
40. 40.🔘 Which kind of switch closes when tipped over? (a) a tilt switch (b) a toggle switch (c) a slide switch (d) a push button

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