Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 556 · 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.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the input (c) the process (d) the battery
2. 2.⚡ A 36 W device works on 12 V. What current does it take (in amperes)? =
3. 3.True or false: if a wire is cut, the circuit is open and no current flows. (a) False (b) True
4. 4.⚡ Power tells us … (a) energy used each second (b) the length of a wire (c) the colour of light (d) the size of a cell
5. 5.💡 A blue LED uses 3 V and should get 25 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
6. 6.🤖 if (light < 200) { lamp ON } else { lamp OFF }
   The light sensor reads 339. What happens? (a) lamp OFF (b) lamp ON
7. 7.Which of these is a conductor? (a) a brass key (b) a rubber band (c) a plastic ruler (d) a dry cork
8. 8.🔁 x = 1
   repeat 3 times { x = x × 2 }
   What is x at the end?
9. 9.True or false: a siren mainly makes sound. (a) True (b) False
10. 10.🧾 A 1500 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
11. 11.True or false: “own switch for each bulb” is true of a parallel circuit. (a) True (b) False
12. 12.Which of these is not safe? (a) stop if a part gets hot (b) use a cable with cuts (c) take cells out after use (d) build with an adult near
13. 13.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) No (b) Yes
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 ON, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
15. 15.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a paper strip. Does the bulb glow? (a) Yes (b) No
16. 16.True or false: a safety pin is a conductor. (a) True (b) False
17. 17.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
18. 18.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) the longer line (d) neither line
19. 19.🔍 Which is the odd one out? (a) leave the TV on standby (b) close the fridge quickly (c) use old filament bulbs (d) iron one shirt at a time
20. 20.🌈 A gold fourth band on a resistor means the value may be off by … (a) 25 % (b) 0 % (c) 5 % (d) 50 %
21. 21.📏 Which unit measures resistance? (a) ampere (A) (b) ohm (Ω) (c) volt (V) (d) watt (W)
22. 22.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
23. 23.Which of these is safe? (a) poke things in a socket (b) touch a fallen wire (c) use small battery cells (d) touch a switch when wet
24. 24.Which job is done by the USB port? (a) runs the program (b) shows the board is on (c) brings power and code (d) connect sensors and LEDs
25. 25.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
26. 26.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
27. 27.🔦 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 cotton thread. Does the bulb glow? (a) No (b) Yes
28. 28.True or false: a circle with an X in it is the symbol for a bulb. (a) True (b) False
29. 29.⏱️ A program says “wait 6250 ms”. How many seconds is that? =
30. 30.🌈 In the resistor colour code, which number does blue stand for?
31. 31.🔍 An object is 51 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
32. 32.🔍 A distance sensor sends a sound pulse and hears the echo 8 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
33. 33.🤖 Microcontroller or laptop: which one runs one small program? (a) microcontroller (b) laptop
34. 34.🌐 Is a plain table fan an IoT device? (a) an IoT device (b) not an IoT device
35. 35.📏 Which unit measures current? (a) volt (V) (b) ohm (Ω) (c) watt (W) (d) ampere (A)
36. 36.What does a tilt switch do? (a) works only while pressed (b) closes when tipped over (c) stays where you flip it (d) closes near a magnet
37. 37.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
38. 38.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 150 ms }
    How many times does the LED blink in 3 seconds?
39. 39.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
40. 40.True or false: a circle with A inside is the symbol for a voltmeter. (a) True (b) False

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