Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 91 · 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.True or false: one tall, one short bar is the symbol for a wire. (a) True (b) False
2. 2.💡 An LED is joined to a 9 V battery through a 1000 Ω resistor; its long leg goes to the − side and its short leg to the + side. What happens? (a) lights up (b) does not light (c) may burn out
3. 3.🌐 In an IoT system, which part measures the real world? (a) cloud server (b) actuator (c) Wi-Fi (d) sensor
4. 4.True or false: a fuse has coloured bands. (a) False (b) True
5. 5.Which of these is a risky habit? (a) share only needed data (b) read app permissions (c) change default passwords (d) accept every permission
6. 6.⏱️ How many milliseconds is a wait of 2.3 seconds?
7. 7.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
   set pin 8 LOW
   set pin 8 LOW
   set pin 7 HIGH
   Is the LED ON or OFF at the end? (a) OFF (b) ON
8. 8.🔘 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 ON. Does the bulb glow? (a) No (b) Yes
9. 9.🔌 Most metals are good … (a) conductors (b) batteries (c) insulators (d) magnets only
10. 10.🔁 What do we call a circuit with a break in it? (a) a series circuit (b) a closed circuit (c) a full circuit (d) an open circuit
11. 11.🧩 Which component turns a fan or wheels? (a) resistor (b) buzzer (c) capacitor (d) motor
12. 12.🤖 Microcontroller or laptop: which one runs one small program? (a) laptop (b) microcontroller
13. 13.💡 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
14. 14.Which of these is safe? (a) build with an adult near (b) touch a fallen wire (c) throw cells in a fire (d) poke things in a socket
15. 15.🔢 To run one loop of a plant-watering program, which comes first: “switch the pump on/off” or “compare with the limit”? (a) switch the pump on/off (b) compare with the limit
16. 16.True or false: “one bulb out, all go out” is true of a series circuit. (a) True (b) False
17. 17.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
18. 18.⚡ A cell changes stored chemical energy into which kind of energy? (a) nuclear energy (b) sound energy (c) wind energy (d) electrical energy
19. 19.True or false: a thermistor senses how hot it is. (a) False (b) True
20. 20.💡 2 identical bulbs are in parallel and each one takes 1.5 A. What total current (in amperes) comes from the battery? =
21. 21.⚙️ What is an actuator? (a) a battery (b) a program (c) a sensor (d) an output that acts
22. 22.🔁 count = 5
    repeat 7 times { count = count + 6 }
    What is count at the end?
23. 23.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 1 hour?
24. 24.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) a safe circuit (c) a short circuit (d) an open circuit
25. 25.🤖 if (light < 300 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
26. 26.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V ÷ R (c) I = V × R (d) I = R ÷ V
27. 27.🗺️ In an input → process → output plan, is “decide if soil is dry” the input, the process or the output? (a) input (b) output (c) process
28. 28.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they keep glowing (b) they explode (c) they get dimmer (d) they all go out
29. 29.🔌 Is a turning knob an input or an output for a microcontroller? (a) output (b) input
30. 30.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) input (b) process (c) output
31. 31.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) dotted circles (c) straight lines (d) wavy lines
32. 32.Which drawing is the symbol for a resistor? (a) a dot where wires meet (b) one tall, one short bar (c) a plain rectangle (d) a line lifted at a gap
33. 33.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a diode (c) a resistor (d) a buzzer
34. 34.🔍 Which is the odd one out? (a) a siren (b) a doorbell (c) an electric drill (d) a loudspeaker
35. 35.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
36. 36.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 60 (c) 1000 (d) 10
37. 37.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 270 Ω resistor? (a) red-violet-red (b) red-violet-black (c) red-violet-brown (d) violet-red-brown
38. 38.⏱️ A program says “wait 3000 ms”. How many seconds is that? =
39. 39.💡 What does LED stand for? (a) light energy dial (b) large electric dial (c) low energy device (d) light-emitting diode
40. 40.Which of these is an IoT device? (a) a fitness band with app (b) a wind-up clock (c) a plain table fan (d) a pencil sharpener

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids