Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 545 · 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.⚠️ Is it safe to use a cable with cuts? (a) safe (b) not safe
2. 2.🌈 A resistor has the colour bands green, red, brown. What is its value (in ohms)?
3. 3.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = I ÷ V (c) R = V ÷ I (d) R = V + I
4. 4.🤖 Microcontroller or laptop: which one has no screen of its own? (a) microcontroller (b) laptop
5. 5.🔍 Which is the odd one out? (a) use small battery cells (b) fly kites in open fields (c) use mains for a project (d) keep drinks far away
6. 6.🔺 A 4 V supply is joined across a 200 Ω resistor. What current flows (in milliamperes, mA)?
7. 7.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 220 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
8. 8.🔘 A cell and a bulb are joined to 4 side-by-side paths with one switch on each path — A, B, C and D (parallel). A is OFF, B is OFF, C is ON and D is ON. Does the bulb glow? (a) No (b) Yes
9. 9.🔍 For a microcontroller, is a sensor an input or an output? (a) a power source (b) an input (c) a fuse (d) an output
10. 10.🔁 repeat 6 times { repeat 2 times { beep } }
    How many beeps are there?
11. 11.⚡ A home appliance on the 230 V mains takes 4 A. What is its power (in watts)?
12. 12.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a resistor (d) a buzzer
13. 13.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
14. 14.🌐 Is an app-controlled bulb an IoT device? (a) an IoT device (b) not an IoT device
15. 15.⚡ A 4.5 W device works on 1.5 V. What current does it take (in amperes)? =
16. 16.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) the else part (c) the if part (d) both parts
17. 17.⏱️ loop forever { LED ON; wait 850 ms; LED OFF; wait 1150 ms }
    How many times does the LED blink in 6 seconds?
18. 18.🔋 How many volts does one ordinary torch cell give? (a) 1.5 V (b) 0.5 V (c) 230 V (d) 15 V
19. 19.Which of these is a conductor? (a) a woollen thread (b) a glass marble (c) an iron nail (d) a plastic ruler
20. 20.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
21. 21.True or false: “a button press” is the input. (a) True (b) False
22. 22.🤖 “if (A AND B)” is true when … (a) only B is true (b) both are false (c) only A is true (d) both A and B are true
23. 23.🧮 Two resistors in parallel give a total that is … (a) their sum (b) always zero (c) less than either one (d) more than either one
24. 24.⚡ A device works on 1.5 V and takes 1.5 A. What is its power (in watts)? =
25. 25.🧩 Which component turns a fan or wheels? (a) capacitor (b) motor (c) resistor (d) thermistor
26. 26.🌈 A resistor has the colour bands blue, black, yellow. What is its value in kilo-ohms (kΩ)? =
27. 27.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I + R (c) V = I ÷ R (d) V = I × R
28. 28.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 1000 (d) 60
29. 29.🔍 Which is the odd one out? (a) reuse one password (b) log out of shared phones (c) cover unused cameras (d) share only needed data
30. 30.True or false: if a wire has come loose, the circuit is closed and current flows. (a) True (b) False
31. 31.Which of these is a risky habit? (a) ignore update messages (b) read app permissions (c) set up with a parent (d) change default passwords
32. 32.📏 How many milliamperes (mA) make 1 ampere? (a) 10 (b) 1000 (c) 60 (d) 100
33. 33.⏱️ What does “wait 500 ms” do? (a) pauses for half a second (b) turns the LED off (c) blinks 500 times (d) waits 500 seconds
34. 34.⚡ A cell changes stored chemical energy into which kind of energy? (a) sound energy (b) wind energy (c) nuclear energy (d) electrical energy
35. 35.💡 5 identical bulbs are joined in series with a 20 V battery (ideal wires). How many volts does each bulb get? =
36. 36.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
37. 37.True or false: resistance is measured in ohms (Ω). (a) True (b) False
38. 38.✏️ Why do engineers draw circuits with symbols? (a) to make it colourful (b) quick and clear for all (c) symbols are heavier (d) to hide the circuit
39. 39.Which job is done by the reset button? (a) runs the program (b) shows the board is on (c) keeps the voltage steady (d) restarts the program
40. 40.Which of these is the output? (a) a button press (b) a temperature reading (c) compare with a limit (d) an alert on the phone

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