Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 92 · 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.🔗 Series or parallel circuit: “one bulb out, all go out”? (a) series (b) parallel
2. 2.Which job needs a sound sensor? (a) water a dry plant (b) switch on with a clap (c) switch on lamps at dusk (d) make a parking alarm
3. 3.True or false: to stop a robot near walls, use a temperature sensor. (a) False (b) True
4. 4.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
   The light reading is 500 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
5. 5.💡 5 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
6. 6.True or false: a laptop runs one small program. (a) True (b) False
7. 7.🔍 Which is the odd one out? (a) compare with a limit (b) check if temp > 30 (c) decide if soil is dry (d) a motion sensor signal
8. 8.🌈 In the resistor colour code, which number does red stand for?
9. 9.🏠 Which is a smart-home example? (a) a printed map (b) a hand fan (c) a candle in a jar (d) lights on from an app
10. 10.True or false: to open a phone charger is not safe. (a) False (b) True
11. 11.⚡ A cell changes stored chemical energy into which kind of energy? (a) wind energy (b) electrical energy (c) nuclear energy (d) sound energy
12. 12.🧮 A 1.6 V battery is joined to 3 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
13. 13.⚙️ Which actuator would you use to beep an alarm? (a) a buzzer (b) a servo motor (c) a pump (d) an LED
14. 14.⏱️ loop forever { LED ON; wait 600 ms; LED OFF; wait 450 ms }
    How many milliseconds does one blink (ON + OFF) take?
15. 15.🔐 Why install updates on IoT devices? (a) they delete the Wi-Fi (b) they make it heavier (c) they fix security holes (d) they change the colour
16. 16.🌐 Is a pencil sharpener an IoT device? (a) an IoT device (b) not an IoT device
17. 17.🔺 A 16.5 V supply is joined across a 330 Ω resistor. What current flows (in milliamperes, mA)?
18. 18.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) only one (b) none (c) both of them (d) it does not matter
19. 19.⚠️ What protects home wiring by melting or tripping when too much current flows? (a) a long wire (b) a fuse or MCB (c) a plug top (d) a bulb
20. 20.🔺 A current of 0.25 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
21. 21.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) symbols are heavier (c) to hide the circuit (d) to make it colourful
22. 22.🔋 On a cell, does “usually the black wire” mean the + end or the − end? (a) + (positive) (b) − (negative)
23. 23.What does a push button do? (a) works only while pressed (b) closes when tipped over (c) closes near a magnet (d) flips up or down
24. 24.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
25. 25.🤖 if (distance < 30) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 35 cm. What happens? (a) buzzer is silent (b) buzzer beeps
26. 26.🌐 A weather station sends one reading every 5 seconds. How many readings does it send in 1 minute?
27. 27.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) plastic is an insulator (c) to make them heavy (d) plastic is a conductor
28. 28.💡 2 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
29. 29.Which of these is an input? (a) an LED (b) a keypad (c) a servo motor (d) a speaker
30. 30.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 2000 Ω resistor? (a) red-black-brown (b) orange-red-red (c) red-black-red (d) red-black-orange
31. 31.🧮 Two resistors in parallel give a total that is … (a) always zero (b) their sum (c) less than either one (d) more than either one
32. 32.🤖 Microcontroller or laptop: which one needs much more power? (a) laptop (b) microcontroller
33. 33.True or false: two equal parallel lines is the symbol for a cell. (a) False (b) True
34. 34.Which of these is a conductor? (a) a paper strip (b) a safety pin (c) a plastic straw (d) a wooden stick
35. 35.Which of these means the circuit is open? (a) the switch is OFF (b) the loop is complete (c) all wires are joined (d) the switch is ON
36. 36.Which of these is measured in watts (W)? (a) resistance (b) energy used each second (c) current (d) the flow of charge
37. 37.⚡ A 1.2 W device works on 6 V. What current does it take (in amperes)? =
38. 38.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) type it all in (b) post it online (c) ask a parent first (d) share it with friends
39. 39.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
40. 40.🔌 Which part of a screwdriver should an electrician hold? (a) the steel shaft (b) the bare end (c) the plastic handle (d) the metal tip

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