Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 666 · 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 safe? (a) climb an electric pole (b) stop if a part gets hot (c) use mains for a project (d) fly a kite near wires
2. 2.🤖 if (temperature > 28) { fan ON } else { fan OFF }
   The temperature sensor reads 27 °C. What happens? (a) fan ON (b) fan OFF
3. 3.📶 Digital or analog: a button: pressed or not? (a) analog (b) digital
4. 4.🔺 A 1.6 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
5. 5.💡 A battery lights 4 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
6. 6.What does a tilt switch do? (a) closes near a magnet (b) closes when tipped over (c) springs back when let go (d) stays where you flip it
7. 7.⚡ Power tells us … (a) the size of a cell (b) the colour of light (c) the length of a wire (d) energy used each second
8. 8.🔁 count = 4
   repeat 4 times { count = count + 3 }
   What is count at the end?
9. 9.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
10. 10.Which job needs a pump? (a) spin a robot’s wheels (b) show the temperature (c) move water to plants (d) open a gate to 90°
11. 11.🔋 On a cell, does “the end with a bump” mean the + end or the − end? (a) − (negative) (b) + (positive)
12. 12.Which of these is safe? (a) climb an electric pole (b) build with an adult near (c) throw cells in a fire (d) use a cable with cuts
13. 13.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
14. 14.🔍 An object is 187 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
15. 15.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 31 °C. What is shown? (a) Cool (b) Hot (c) Warm
16. 16.🔁 repeat 2 times { repeat 5 times { beep } }
    How many beeps are there?
17. 17.True or false: to touch a fallen wire is safe. (a) False (b) True
18. 18.🔺 A current of 10 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
19. 19.⚠️ Is it safe to dry your hands first? (a) not safe (b) safe
20. 20.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 7400 Ω resistor? (a) violet-yellow-brown (b) violet-yellow-red (c) violet-yellow-orange (d) yellow-violet-red
21. 21.⏱️ How many milliseconds is a wait of 2.7 seconds?
22. 22.🧮 A 4 V battery is joined to 5 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
23. 23.True or false: on an LED, the shorter leg is the anode (+). (a) True (b) False
24. 24.⏱️ A program says “wait 500 ms”. How many seconds is that? =
25. 25.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is OFF, B is ON and C is ON. Does the bulb glow? (a) No (b) Yes
26. 26.🔋 Cells joined + to − in a row (series) give … (a) the same voltage (b) no voltage (c) a bigger voltage (d) a smaller voltage
27. 27.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
28. 28.Which of these means the circuit is open? (a) the loop is complete (b) the switch is ON (c) a cell is taken out (d) all wires are joined
29. 29.⏱️ repeat 3 times { buzzer ON; wait 300 ms; buzzer OFF; wait 200 ms }
    How many milliseconds does this take in all?
30. 30.✏️ In a circuit diagram, which part is drawn as a straight line? (a) wire (b) diode (c) voltmeter (d) cell
31. 31.⏱️ repeat 4 times { buzzer ON; wait 900 ms; buzzer OFF; wait 100 ms }
    How many milliseconds does this take in all?
32. 32.🌐 A soil sensor sends a reading to an app every 10 minutes. How many readings arrive in 2 hours?
33. 33.Which job needs an LED? (a) beep an alarm (b) turn to an exact angle (c) show a status light (d) spin a robot’s wheels
34. 34.True or false: a reed switch slides side to side. (a) True (b) False
35. 35.🔐 Privacy for a smart device means controlling … (a) how loud it beeps (b) its colour (c) who can see your data (d) its battery size
36. 36.🧮 A 10 Ω resistor is joined in series with two equal 50 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
37. 37.🧭 Which part of a microcontroller board shows the board is on? (a) the main chip (b) the reset button (c) the pins (d) the power LED
38. 38.Which of these is not safe? (a) keep drinks far away (b) build with an adult near (c) take cells out after use (d) poke things in a socket
39. 39.⏱️ How many milliseconds is a wait of 1.6 seconds?
40. 40.📏 How many ohms (Ω) is 3.6 kΩ?

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