Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 8 · 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.🔍 Which is the odd one out? (a) close the fridge quickly (b) use LED lamps (c) iron one shirt at a time (d) switch off empty rooms
2. 2.Which of these is the input? (a) an alert on the phone (b) check if temp > 30 (c) decide if soil is dry (d) a soil moisture reading
3. 3.✏️ In a circuit diagram, wires are usually drawn as … (a) dotted circles (b) little stars (c) wavy lines (d) straight lines
4. 4.What does a diode do? (a) lets current go one way (b) senses how hot it is (c) blows if current is high (d) beeps for an alarm
5. 5.Which job is done by the reset button? (a) brings power and code (b) shows the board is on (c) restarts the program (d) runs the program
6. 6.🔍 Which is the odd one out? (a) a keypad (b) a push button (c) a sound sensor (d) an LED
7. 7.Which of these is a conductor? (a) a paper strip (b) a graphite rod (c) a cotton thread (d) a glass marble
8. 8.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
9. 9.⚡ What does a tube light mainly change electricity into? (a) heat (b) movement (c) sound (d) light
10. 10.✏️ In a circuit diagram, which part is drawn as a circle with M inside? (a) resistor (b) voltmeter (c) motor (d) wire
11. 11.🔍 Which is the odd one out? (a) a steel spoon (b) a dry cork (c) an iron nail (d) a safety pin
12. 12.🔍 Which is the odd one out? (a) keep factory passwords (b) ignore update messages (c) cover unused cameras (d) reuse one password
13. 13.True or false: to take cells out after use is safe. (a) False (b) True
14. 14.🔦 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 brass key. Does the bulb glow? (a) Yes (b) No
15. 15.⚡ A 2.4 W device works on 24 V. What current does it take (in amperes)? =
16. 16.🔁 What does “count = count + 1” do? (a) takes 1 away (b) sets count to 1 (c) prints 1 (d) adds 1 to count
17. 17.🔍 Which is the odd one out? (a) a ceramic cup (b) a cotton thread (c) a steel spoon (d) a glass marble
18. 18.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
19. 19.💡 4 identical bulbs are joined in parallel across a 4.5 V battery (ideal wires). How many volts does each bulb get? =
20. 20.🤖 How does a new program get onto a microcontroller board? (a) typed on the chip (b) sent by sound (c) drawn with a pen (d) uploaded over USB
21. 21.What does a slide switch do? (a) slides side to side (b) works only while pressed (c) flips up or down (d) stays where you flip it
22. 22.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) to hide the circuit (c) symbols are heavier (d) quick and clear for all
23. 23.🔁 x = 2
    repeat 1 time { x = x × 2 }
    What is x at the end?
24. 24.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
25. 25.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) no voltage (c) a smaller voltage (d) a bigger voltage
26. 26.True or false: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
27. 27.Which of these saves electricity? (a) leave fridge door open (b) run fans in empty rooms (c) iron one shirt at a time (d) set the AC to 24 °C
28. 28.🔺 A 12 V supply is joined across a 12 Ω resistor. What current flows (in amperes)? =
29. 29.🔺 A current of 0.1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
30. 30.True or false: a transistor lets current go one way. (a) False (b) True
31. 31.⏱️ repeat 9 times { buzzer ON; wait 800 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
32. 32.🌈 A resistor has the colour bands blue, black, yellow. What is its value in kilo-ohms (kΩ)? =
33. 33.🔍 Which is the odd one out? (a) an LED lights up (b) a light level reading (c) a soil moisture reading (d) a temperature reading
34. 34.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a steel spoon across the gap. Does the bulb glow? (a) No (b) Yes
35. 35.True or false: a glass marble is an insulator. (a) False (b) True
36. 36.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
37. 37.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
38. 38.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 160 Ω resistor? (a) brown-blue-brown (b) brown-blue-black (c) blue-brown-brown (d) brown-blue-red
39. 39.💡 3 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
40. 40.🔌 Is a motor an input or an output for a microcontroller? (a) input (b) output

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