Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 823 · 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.🔋 Identical cells side by side (in parallel) give … (a) no voltage (b) the same voltage (c) half the voltage (d) double the voltage
2. 2.🧮 Adding another resistor in series makes the total resistance … (a) bigger (b) zero (c) smaller (d) stay the same
3. 3.🤖 if (temperature > 32) { fan ON } else { fan OFF }
   The temperature sensor reads 32 °C. What happens? (a) fan OFF (b) fan ON
4. 4.🔌 Is a small display an input or an output for a microcontroller? (a) input (b) output
5. 5.🔢 To run one loop of a plant-watering program, which comes first: “compare with the limit” or “wait a few seconds”? (a) wait a few seconds (b) compare with the limit
6. 6.⚠️ Why must we never touch switches with wet hands? (a) water makes it cold (b) it spoils the paint (c) water carries current (d) it is just untidy
7. 7.What does a reed switch do? (a) works only while pressed (b) flips up or down (c) closes when tipped over (d) closes near a magnet
8. 8.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
9. 9.🧮 Resistors of 150 Ω, 10 Ω and 68 Ω are joined in series. What is the total resistance (in ohms)?
10. 10.Which job is done by the pins? (a) shows the board is on (b) connect sensors and LEDs (c) restarts the program (d) brings power and code
11. 11.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
12. 12.⚡ A device works on 1.5 V and takes 0.2 A. What is its power (in watts)? =
13. 13.📏 Which unit measures how much a part resists? (a) ohm (Ω) (b) ampere (A) (c) watt (W) (d) volt (V)
14. 14.Which of these is measured in ohms (Ω)? (a) voltage (b) the flow of charge (c) energy used each second (d) resistance
15. 15.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) both parts (b) the if part (c) the else part (d) neither part
16. 16.What does an LDR do? (a) senses how hot it is (b) glows using little power (c) senses how bright it is (d) limits the current
17. 17.💡 Why is house wiring done in parallel? (a) so all go off together (b) each gets full voltage (c) to make bulbs dim (d) to save copper only
18. 18.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
19. 19.⏱️ A program says “wait 1500 ms”. How many seconds is that? =
20. 20.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
21. 21.🔦 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) Yes (b) No
22. 22.True or false: to post your live location is a good habit. (a) False (b) True
23. 23.⚡ A home appliance on the 230 V mains takes 10 A. What is its power (in watts)?
24. 24.What does the Wi-Fi link do? (a) shows data to you (b) carries the data (c) stores data online (d) reads values, decides
25. 25.Which of these mainly makes movement? (a) an electric iron (b) a street light (c) a tube light (d) an exhaust fan
26. 26.🔺 A current of 40 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
27. 27.✏️ In a circuit diagram, which part is drawn as two equal parallel lines? (a) diode (b) capacitor (c) wire (d) cell
28. 28.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) not joined (b) in series (c) by Wi-Fi (d) in parallel
29. 29.💡 What does LED stand for? (a) light-emitting diode (b) large electric dial (c) low energy device (d) light energy dial
30. 30.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) capacitor (b) resistor (c) junction (d) voltmeter
31. 31.🔁 What do we call a circuit with a break in it? (a) an open circuit (b) a closed circuit (c) a series circuit (d) a full circuit
32. 32.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
33. 33.⚙️ What is an actuator? (a) a battery (b) a sensor (c) an output that acts (d) a program
34. 34.🔍 Which is the odd one out? (a) accept every permission (b) share camera links (c) ignore update messages (d) change default passwords
35. 35.🔐 Privacy for a smart device means controlling … (a) its colour (b) who can see your data (c) its battery size (d) how loud it beeps
36. 36.⚡ A device works on 12 V and takes 1.5 A. What is its power (in watts)? =
37. 37.🔢 To get a sensor reading onto a phone, what comes right after “the sensor measures”? (a) the app shows it (b) it is sent by Wi-Fi (c) the board reads it (d) the cloud stores it
38. 38.🧮 A 6.5 V battery is joined to 3 Ω and 10 Ω resistors in series. What current flows (in amperes)? =
39. 39.🔺 A current of 1.5 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
40. 40.Which of these is safe? (a) open a phone charger (b) build with an adult near (c) fly a kite near wires (d) poke things in a socket

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