Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 890 · 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.True or false: a microcontroller needs much more power. (a) True (b) False
2. 2.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 7 HIGH
   set pin 8 HIGH
   set pin 7 LOW
   set pin 8 LOW
   Is the LED ON or OFF at the end? (a) ON (b) OFF
3. 3.💡 5 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 5 is taken out of its holder. Does bulb 2 glow? (a) No (b) Yes
4. 4.True or false: a metal paper clip is an insulator. (a) False (b) True
5. 5.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False
6. 6.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. Does the bulb glow? (a) No (b) Yes
7. 7.Which of these is safe? (a) poke things in a socket (b) use a cable with cuts (c) touch a fallen wire (d) dry your hands first
8. 8.✏️ In a circuit diagram, wires are usually drawn as … (a) straight lines (b) dotted circles (c) little stars (d) wavy lines
9. 9.Which of these means the circuit is closed? (a) the switch is OFF (b) all wires are joined (c) a wire has come loose (d) the bulb is unscrewed
10. 10.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
11. 11.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) to hide the circuit (c) to make it colourful (d) symbols are heavier
12. 12.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 900 ms }
    How many times does the LED blink in 8 seconds?
13. 13.What does a toggle switch do? (a) works only while pressed (b) springs back when let go (c) stays where you flip it (d) slides side to side
14. 14.📏 In the water-pipe picture of a circuit, resistance is like … (a) a bigger tank (b) a narrow pipe (c) the flow of water (d) the water pressure
15. 15.🔺 A 3 V supply is joined across a 120 Ω resistor. What current flows (in milliamperes, mA)?
16. 16.Which of these is a good habit? (a) accept every permission (b) reuse one password (c) ignore update messages (d) set up with a parent
17. 17.⚡ A 0.75 W device works on 1.5 V. What current does it take (in amperes)? =
18. 18.⚡ What do we call a flow of electric charge through a wire? (a) friction (b) a magnet (c) electric current (d) sound
19. 19.Which job needs a motion sensor? (a) measure classroom noise (b) switch on lamps at dusk (c) open blinds at sunrise (d) spot someone walking in
20. 20.⚡ Which tiny particles drift along a metal wire to carry the current? (a) water drops (b) electrons (c) photons (d) dust particles
21. 21.🔐 Is it a good or a risky habit to share camera links? (a) good habit (b) risky habit
22. 22.🔋 4 identical 3 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
23. 23.🔘 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 ON, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
24. 24.✏️ In a circuit diagram, which part is drawn as a circle with an X in it? (a) voltmeter (b) diode (c) bulb (d) LED
25. 25.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they explode (d) they get dimmer
26. 26.True or false: to log out of shared phones is a good habit. (a) False (b) True
27. 27.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V + R (d) I = V × R
28. 28.🔺 A current of 2.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
29. 29.🔁 repeat 6 times { repeat 2 times { beep } }
    How many beeps are there?
30. 30.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 170 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
31. 31.True or false: a resistor glows using little power. (a) True (b) False
32. 32.🧮 A 2.2 V battery is joined to 10 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
33. 33.⚡ A device works on 3 V and takes 3 A. What is its power (in watts)? =
34. 34.🔍 Which is the odd one out? (a) set a strong password (b) set up with a parent (c) reuse one password (d) install software updates
35. 35.📏 How many kilowatts (kW) is 3250 W? =
36. 36.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 5 V supply. What resistor (in ohms) is needed in series?
37. 37.🔍 Which is the odd one out? (a) a glass marble (b) a ceramic cup (c) an iron nail (d) a plastic ruler
38. 38.💡 4 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
39. 39.🔋 3 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
40. 40.True or false: a woollen thread is an insulator. (a) False (b) True

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