Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 833 · 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 a risky habit? (a) log out of shared phones (b) cover unused cameras (c) set up with a parent (d) keep factory passwords
2. 2.🔌 Is a temperature sensor an input or an output for a microcontroller? (a) output (b) input
3. 3.🔘 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 OFF. Does the bulb glow? (a) No (b) Yes
4. 4.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
5. 5.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in parallel (d) in series
6. 6.🧮 A 0.7 V battery is joined to 3 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
7. 7.⏱️ loop forever { LED ON; wait 1550 ms; LED OFF; wait 450 ms }
   How many times does the LED blink in 10 seconds?
8. 8.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) the if part (b) neither part (c) both parts (d) the else part
9. 9.🧩 Which part changes electrical energy into sound? (a) a diode (b) a resistor (c) a capacitor (d) a buzzer
10. 10.🔁 count = 1
    repeat 10 times { count = count + 9 }
    What is count at the end?
11. 11.🔺 A 1 V supply is joined across a 100 Ω resistor. What current flows (in milliamperes, mA)?
12. 12.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) input (b) output (c) process
13. 13.💡 An LED (with its resistor) is on pin 7. 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
14. 14.🌐 Each reading a sensor sends is 20 bytes. How many bytes do 90 readings take?
15. 15.Which of these is true of a parallel circuit? (a) a single current path (b) own switch for each bulb (c) one bulb out, all go out (d) a break stops every bulb
16. 16.True or false: a diode makes a beeping sound. (a) True (b) False
17. 17.🔍 Which is the odd one out? (a) a safety pin (b) a graphite rod (c) a cotton thread (d) a copper wire
18. 18.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the main chip (b) the power LED (c) the voltage regulator (d) the USB port
19. 19.🔍 Which is the odd one out? (a) a turning knob (b) an LED (c) a motion sensor (d) a keypad
20. 20.Which of these is measured in ohms (Ω)? (a) current (b) energy used each second (c) the push of a cell (d) resistance
21. 21.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
22. 22.🧾 Which lamp gives the same light for the least power? (a) an oil lamp (b) a filament bulb (c) an LED lamp (d) a candle
23. 23.🧮 A 7.5 V battery is joined to 12 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
24. 24.🔁 Is the circuit closed or open if the switch is ON? (a) open (b) closed
25. 25.Which of these is the process? (a) a motion sensor signal (b) a button press (c) the pump turns on (d) count button presses
26. 26.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 12 V (c) 9 V (d) 1.5 V
27. 27.⚡ Which formula gives electric power? (a) P = V ÷ I (b) P = V + I (c) P = V × I (d) P = I ÷ V
28. 28.💡 4 identical bulbs are joined in series with a 12 V battery (ideal wires). How many volts does each bulb get? =
29. 29.⏱️ loop forever { LED ON; wait 50 ms; LED OFF; wait 350 ms }
    How many times does the LED blink in 18 seconds?
30. 30.Which job is done by the pins? (a) runs the program (b) connect sensors and LEDs (c) keeps the voltage steady (d) brings power and code
31. 31.🔋 4 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
32. 32.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
33. 33.Which drawing is the symbol for a capacitor? (a) a circle with V inside (b) a plain rectangle (c) two equal parallel lines (d) a straight line
34. 34.What does a motor do? (a) senses how hot it is (b) limits the current (c) makes things spin (d) lets current go one way
35. 35.🌐 In an IoT system, which part shows data to you? (a) microcontroller (b) actuator (c) phone app (d) sensor
36. 36.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is ON and C is ON. Does the bulb glow? (a) Yes (b) No
37. 37.🧩 Which component stores a little charge? (a) motor (b) fuse (c) capacitor (d) buzzer
38. 38.🔘 A cell, a bulb and switches A, B, C and D are joined one after another in a single loop (series). A is ON, B is ON, C is OFF and D is ON. Does the bulb glow? (a) Yes (b) No
39. 39.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 0 % (c) 25 % (d) 5 %
40. 40.🧩 Which component boosts a small signal? (a) transistor (b) motor (c) thermistor (d) LDR

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