Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 294 · 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.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
2. 2.💡 3 identical bulbs are joined in parallel across a 9 V battery (ideal wires). How many volts does each bulb get? =
3. 3.What does a resistor do? (a) makes a beeping sound (b) smooths a wobbly supply (c) has coloured bands (d) turns a fan or wheels
4. 4.True or false: triangle, bar and arrows is the symbol for a junction. (a) False (b) True
5. 5.True or false: “bulbs share the voltage” is true of a parallel circuit. (a) True (b) False
6. 6.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 1.5 V (c) 12 V (d) 230 V
7. 7.🔐 Who should decide which smart devices go in a child’s room? (a) the app’s adverts (b) an online stranger (c) a parent or guardian (d) nobody at all
8. 8.📶 How many states can a digital pin have? (a) one (b) ten (c) two (d) a thousand
9. 9.True or false: a wind-up toy usually has a microcontroller inside. (a) False (b) True
10. 10.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) takes 1 away (d) adds 1 to count
11. 11.💡 5 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?
12. 12.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 HIGH
    set pin 8 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
13. 13.🔋 8 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
14. 14.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) straight lines (c) dotted circles (d) wavy lines
15. 15.🔁 x = 1
    repeat 5 times { x = x × 2 }
    What is x at the end?
16. 16.🔍 Which is the odd one out? (a) a servo motor (b) a speaker (c) a buzzer (d) a keypad
17. 17.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) process (b) input (c) output
18. 18.🤖 Does a plain wall switch usually have a microcontroller inside? (a) Yes (b) No
19. 19.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 570 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
20. 20.🧩 Which part changes electrical energy into movement? (a) a motor (b) a fuse (c) an LED (d) a resistor
21. 21.⚡ A device works on 9 V and takes 3 A. What is its power (in watts)? =
22. 22.💡 A battery lights 2 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.🧮 A 6.5 V battery is joined to 5 Ω and 8 Ω resistors in series. What current flows (in amperes)? =
24. 24.🔁 repeat 3 times { repeat 5 times { beep } }
    How many beeps are there?
25. 25.Which job needs a pump? (a) spin a robot’s wheels (b) open a gate to 90° (c) move water to plants (d) show a status light
26. 26.🌈 A resistor has the colour bands grey, yellow, red. What is its value (in ohms)?
27. 27.🤖 Does a spinning top usually have a microcontroller inside? (a) No (b) Yes
28. 28.🌈 Which band is read first on a resistor? (a) any band (b) the gold band (c) the widest gap (d) the one nearest an end
29. 29.🧾 Which lamp gives the same light for the least power? (a) a filament bulb (b) an LED lamp (c) an oil lamp (d) a candle
30. 30.🔺 A current of 10 mA flows through a 120 Ω resistor. What is the voltage across it (in volts)? =
31. 31.🔁 count = 1
    repeat 6 times { count = count + 6 }
    What is count at the end?
32. 32.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
33. 33.🔁 count = 6
    repeat 10 times { count = count + 4 }
    What is count at the end?
34. 34.⏱️ A program says “wait 10000 ms”. How many seconds is that? =
35. 35.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
36. 36.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 100 ms }
    How many times does the LED blink in 2 seconds?
37. 37.✏️ In a cell symbol, which line is the + terminal? (a) neither line (b) the shorter line (c) the longer line (d) both lines
38. 38.💡 A red LED (it uses 2 V) is joined with a 150 Ω resistor to a 2.75 V supply. What current flows (in mA)?
39. 39.🧭 Which part of a microcontroller board brings power and code? (a) the USB port (b) the power LED (c) the pins (d) the reset button
40. 40.🌐 Is a pencil sharpener an IoT device? (a) not an IoT device (b) an IoT device

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