Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 426 · 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 not an IoT device? (a) a plain wall switch (b) a smart energy meter (c) a Wi-Fi doorbell camera (d) an app-controlled bulb
2. 2.🧮 Resistors of 33 Ω, 20 Ω and 220 Ω are joined in series. What is the total resistance (in ohms)?
3. 3.📶 Digital or analog: the room temperature? (a) digital (b) analog
4. 4.What does a transistor do? (a) stores a little charge (b) boosts a small signal (c) senses how hot it is (d) glows using little power
5. 5.🧮 A 0.5 V battery is joined to 3 Ω and 2 Ω resistors in series. What current flows (in amperes)? =
6. 6.True or false: “a single current path” is true of a series circuit. (a) False (b) True
7. 7.⚡ Power tells us … (a) the length of a wire (b) the colour of light (c) energy used each second (d) the size of a cell
8. 8.True or false: a push button works only while pressed. (a) True (b) False
9. 9.⏱️ A program says “wait 6250 ms”. How many seconds is that? =
10. 10.🧮 Three equal 75 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
11. 11.Which of these is safe? (a) poke things in a socket (b) take cells out after use (c) open a phone charger (d) fly a kite near wires
12. 12.⏱️ What does “wait 500 ms” do? (a) turns the LED off (b) pauses for half a second (c) waits 500 seconds (d) blinks 500 times
13. 13.True or false: “a door: open or shut” is an analog signal. (a) True (b) False
14. 14.Which of these is a risky habit? (a) cover unused cameras (b) log out of shared phones (c) reuse one password (d) set a strong password
15. 15.⚡ What does a night lamp mainly change electricity into? (a) light (b) sound (c) heat (d) movement
16. 16.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to store charge (c) to change its colour (d) to limit the current
17. 17.⏱️ repeat 4 times { buzzer ON; wait 900 ms; buzzer OFF; wait 800 ms }
    How many milliseconds does this take in all?
18. 18.Which of these mainly gives out heat? (a) an exhaust fan (b) a ceiling fan (c) a school bell (d) a toaster
19. 19.📏 In the water-pipe picture of a circuit, current is like … (a) the water pressure (b) a narrow pipe (c) the flow of water (d) the pipe colour
20. 20.💡 An LED is joined to a 3 V battery through a 470 Ω resistor; the leg next to the flat edge of its rim goes to the + side. What happens? (a) does not light (b) lights up (c) may burn out
21. 21.What does a potentiometer do? (a) turns a fan or wheels (b) is a resistance knob (c) smooths a wobbly supply (d) blows if current is high
22. 22.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
23. 23.🧮 A 10 Ω resistor is joined in series with two equal 10 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
24. 24.Which of these means the circuit is closed? (a) the switch is ON (b) a wire has come loose (c) the switch is OFF (d) a wire is cut
25. 25.🏠 Which is a smart-home example? (a) a hand fan (b) lights on from an app (c) a printed map (d) a candle in a jar
26. 26.🧮 Resistors of 20 Ω, 100 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
27. 27.Which job is done by the USB port? (a) connect sensors and LEDs (b) runs the program (c) restarts the program (d) brings power and code
28. 28.🔁 What does “count = count + 1” do? (a) prints 1 (b) sets count to 1 (c) takes 1 away (d) adds 1 to count
29. 29.🔁 x = 5
    repeat 1 time { x = x × 2 }
    What is x at the end?
30. 30.🔍 Which is the odd one out? (a) log out of shared phones (b) install software updates (c) set up with a parent (d) share the Wi-Fi key
31. 31.🧩 Which part changes electrical energy into movement? (a) a resistor (b) a motor (c) a fuse (d) an LED
32. 32.⚠️ Which power source should children use for electronics projects? (a) an inverter socket (b) a mains extension board (c) a small battery pack (d) a wall socket
33. 33.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
34. 34.True or false: a straight line is the symbol for a wire. (a) False (b) True
35. 35.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 630 Ω resistor? (a) blue-orange-red (b) orange-blue-brown (c) blue-orange-black (d) blue-orange-brown
36. 36.Which of these is not safe? (a) use a cable with cuts (b) dry your hands first (c) take cells out after use (d) fly kites in open fields
37. 37.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
38. 38.💡 In a series circuit, how many paths does the current have? (a) none (b) one for each bulb (c) two (d) one
39. 39.True or false: to throw cells in a fire is not safe. (a) True (b) False
40. 40.What does a push button do? (a) closes near a magnet (b) slides side to side (c) stays where you flip it (d) works only while pressed

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