Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 210 · 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.🔌 Why are electric wires covered in plastic? (a) plastic is an insulator (b) plastic is a conductor (c) to make them heavy (d) plastic makes current
2. 2.⏱️ repeat 5 times { buzzer ON; wait 200 ms; buzzer OFF; wait 700 ms }
   How many milliseconds does this take in all?
3. 3.True or false: if a wire is cut, the circuit is closed and current flows. (a) False (b) True
4. 4.🧮 Adding another resistor in series makes the total resistance … (a) smaller (b) zero (c) stay the same (d) bigger
5. 5.🌈 A resistor has the colour bands green, white, red. What is its value in kilo-ohms (kΩ)? =
6. 6.🔁 Is the circuit closed or open if a cell is taken out? (a) open (b) closed
7. 7.🔌 Is a paper strip a conductor or an insulator? (a) an insulator (b) a conductor
8. 8.⚡ A device works on 5 V and takes 0.1 A. What is its power (in watts)? =
9. 9.True or false: on a cell, “usually the black wire” means the − (negative) end. (a) True (b) False
10. 10.Which of these is safe? (a) stay away from pylons (b) poke things in a socket (c) fly a kite near wires (d) use a cable with cuts
11. 11.🧮 Resistors of 10 Ω, 22 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
12. 12.🔋 On a cell, does “usually the red wire” mean the + end or the − end? (a) − (negative) (b) + (positive)
13. 13.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 0 V (c) 230 V (d) 50 V
14. 14.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
15. 15.🗺️ In “input → process → output”, which part is the decision the program makes? (a) the output (b) the process (c) the battery (d) the input
16. 16.✏️ Why do engineers draw circuits with symbols? (a) to hide the circuit (b) quick and clear for all (c) to make it colourful (d) symbols are heavier
17. 17.🔍 Which is the odd one out? (a) a temperature sensor (b) a speaker (c) a buzzer (d) a water pump
18. 18.🧮 Three equal 30 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
19. 19.Which drawing is the symbol for a voltmeter? (a) a circle with an X in it (b) triangle, bar and arrows (c) a circle with V inside (d) a circle with M inside
20. 20.True or false: on an LED, the shorter leg is the cathode (−). (a) False (b) True
21. 21.🤖 if (light < 200 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 210 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
22. 22.🔘 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 OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
23. 23.💡 What does LED stand for? (a) low energy device (b) light-emitting diode (c) large electric dial (d) light energy dial
24. 24.True or false: “own switch for each bulb” is true of a series circuit. (a) False (b) True
25. 25.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 HIGH
    set pin 8 HIGH
    set pin 8 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
26. 26.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a candle (c) a filament bulb (d) an oil lamp
27. 27.True or false: on a cell, “the shorter symbol line” means the + (positive) end. (a) False (b) True
28. 28.🔦 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
29. 29.🔘 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 ON, B is OFF and C is OFF. Does the bulb glow? (a) No (b) Yes
30. 30.📏 Which unit measures voltage? (a) ampere (A) (b) volt (V) (c) watt (W) (d) ohm (Ω)
31. 31.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
32. 32.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a long wire (b) a fuse or MCB (c) a bulb (d) a plug top
33. 33.True or false: a push button springs back when let go. (a) False (b) True
34. 34.Which job needs a light sensor? (a) warn of a gas leak (b) keep an incubator warm (c) stop a robot near walls (d) open blinds at sunrise
35. 35.True or false: on an LED, the longer leg is the anode (+). (a) True (b) False
36. 36.🔌 Is a motor an input or an output for a microcontroller? (a) output (b) input
37. 37.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 1 minute?
38. 38.🔍 Which is the odd one out? (a) set a strong password (b) change default passwords (c) tap unknown app links (d) turn off unused gadgets
39. 39.⚙️ Which actuator would you use to beep an alarm? (a) a motor (b) a buzzer (c) a pump (d) a servo motor
40. 40.🔁 count = 2
    while (count < 6) { count = count + 2 }
    How many times does the loop run?

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