Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 38 · 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 of these is the process? (a) the pump turns on (b) a motion sensor signal (c) check if temp > 30 (d) the fan starts
2. 2.True or false: to touch a switch when wet is safe. (a) False (b) True
3. 3.💡 Does it save or waste electricity to use daylight to read? (a) saves electricity (b) wastes electricity
4. 4.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets smaller (b) gets bigger (c) stays the same (d) becomes zero
5. 5.⚠️ Is it safe to throw cells in a fire? (a) safe (b) not safe
6. 6.⚡ A 4.8 W device works on 24 V. What current does it take (in amperes)? =
7. 7.🔢 To get a sensor reading onto a phone, which is the LAST step? (a) the board reads it (b) it is sent by Wi-Fi (c) the sensor measures (d) the app shows it
8. 8.🔺 A current of 2.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
9. 9.🤖 if (light < 300) { lamp ON } else { lamp OFF }
   The light sensor reads 236. What happens? (a) lamp OFF (b) lamp ON
10. 10.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
11. 11.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) an output (c) a power source (d) a fuse
12. 12.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is OFF and C is ON. Does the bulb glow? (a) Yes (b) No
13. 13.Which of these usually has a microcontroller inside? (a) a digital alarm clock (b) a plain wall switch (c) a candle (d) a bicycle bell
14. 14.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
15. 15.⚠️ Is it safe to use mains for a project? (a) safe (b) not safe
16. 16.True or false: to use old filament bulbs saves electricity. (a) True (b) False
17. 17.🧮 A 6.5 V battery is joined to 10 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
18. 18.📶 A pin set LOW gives about … (a) 1.5 V (b) 9 V (c) 5 V (d) 0 V
19. 19.🔍 Which is the odd one out? (a) a ceramic cup (b) a steel spoon (c) a metal paper clip (d) a graphite rod
20. 20.🔐 Which is the strongest password for a home smart camera? (a) Tiger#Lamp42!Moon (b) password (c) 123456 (d) admin
21. 21.Which of these is an insulator? (a) a brass key (b) a rubber band (c) a steel coin (d) aluminium foil
22. 22.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) brighter (c) dimmer
23. 23.🤖 if (moisture < 40) { pump ON } else { pump OFF }
    The soil moisture sensor reads 48 %. What happens? (a) pump ON (b) pump OFF
24. 24.🔍 Which is the odd one out? (a) a tube light (b) an electric kettle (c) a water heater (d) an electric iron
25. 25.Which of these is safe? (a) keep drinks far away (b) touch a switch when wet (c) touch a fallen wire (d) use mains for a project
26. 26.🌈 A gold fourth band on a resistor means the value may be off by … (a) 0 % (b) 50 % (c) 5 % (d) 25 %
27. 27.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) resistor (b) bulb (c) motor (d) capacitor
28. 28.⚡ A cell changes stored chemical energy into which kind of energy? (a) nuclear energy (b) electrical energy (c) wind energy (d) sound energy
29. 29.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) a wire has come loose (d) all wires are joined
30. 30.🌈 In the resistor colour code, which number does brown stand for?
31. 31.💡 5 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
32. 32.True or false: on an LED, the round-side leg is the anode (+). (a) False (b) True
33. 33.🔍 Which is the odd one out? (a) a plain wall switch (b) a Wi-Fi smart plug (c) a plain table fan (d) a wind-up clock
34. 34.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a fuse (c) a motor (d) an LED
35. 35.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
36. 36.🔍 Which is the odd one out? (a) a woollen thread (b) a copper wire (c) a metal paper clip (d) an iron nail
37. 37.🔁 count = 9
    repeat 2 times { count = count + 4 }
    What is count at the end?
38. 38.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) half the voltage (c) the same voltage (d) no voltage
39. 39.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 128. What happens? (a) lamp OFF (b) lamp ON
40. 40.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 850 ms }
    How many milliseconds does one blink (ON + OFF) take?

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