Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 758 · 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.🌈 A resistor has the colour bands white, grey, red. What is its value in kilo-ohms (kΩ)? =
2. 2.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
3. 3.Which of these is an IoT device? (a) a pencil sharpener (b) a Wi-Fi weather station (c) a plain wall switch (d) a plain table fan
4. 4.🔺 A current of 0.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
5. 5.Which job needs a gas sensor? (a) water a dry plant (b) close a window in rain (c) start a fan when hot (d) warn of a gas leak
6. 6.🔘 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) No (b) Yes
7. 7.⚡ A home appliance on the 230 V mains takes 0.5 A. What is its power (in watts)?
8. 8.🔺 A 23.5 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
9. 9.⏱️ What does “wait 500 ms” do? (a) blinks 500 times (b) turns the LED off (c) waits 500 seconds (d) pauses for half a second
10. 10.🔁 x = 5
    repeat 4 times { x = x × 2 }
    What is x at the end?
11. 11.True or false: if the bulb is unscrewed, the circuit is open and no current flows. (a) False (b) True
12. 12.🔁 Is the circuit closed or open if a wire is cut? (a) closed (b) open
13. 13.🔗 Series or parallel circuit: “used in house wiring”? (a) parallel (b) series
14. 14.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 16 °C. What is shown? (a) Hot (b) Cool (c) Warm
15. 15.💡 A battery lights 4 identical bulbs joined in parallel. One more identical bulb is added in parallel. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
16. 16.Which of these is an insulator? (a) a rubber band (b) a safety pin (c) aluminium foil (d) a metal paper clip
17. 17.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) stays the same (c) becomes zero (d) gets smaller
18. 18.🔐 Privacy for a smart device means controlling … (a) its colour (b) how loud it beeps (c) who can see your data (d) its battery size
19. 19.🤖 if (moisture < 50) { pump ON } else { pump OFF }
    The soil moisture sensor reads 45 %. What happens? (a) pump ON (b) pump OFF
20. 20.🔐 A smart-camera app asks for your school name and home address. What should you do? (a) ask a parent first (b) type it all in (c) post it online (d) share it with friends
21. 21.🔁 What does “count = count + 1” do? (a) takes 1 away (b) adds 1 to count (c) sets count to 1 (d) prints 1
22. 22.⚡ A solar panel changes which kind of energy into electricity? (a) chemical energy (b) sound energy (c) light energy (d) wind energy
23. 23.True or false: to water a dry plant, use a soil moisture sensor. (a) True (b) False
24. 24.🔋 Does a cell give electricity or use electricity? (a) uses electricity (b) gives electricity
25. 25.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) input (b) process (c) output
26. 26.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) output (c) input
27. 27.What does a fuse do? (a) senses how hot it is (b) lets current go one way (c) stores a little charge (d) blows if current is high
28. 28.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 39 °C. What is shown? (a) Hot (b) Cool (c) Warm
29. 29.🌈 A resistor has the colour bands violet, red, red. What is its value in kilo-ohms (kΩ)? =
30. 30.Which drawing is the symbol for a wire? (a) a circle with an X in it (b) many long-short pairs (c) a long and a short line (d) a straight line
31. 31.🔍 A distance sensor sends a sound pulse and hears the echo 4 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
32. 32.True or false: a push button springs back when let go. (a) True (b) False
33. 33.🗺️ In an input → process → output plan, is “count button presses” the input, the process or the output? (a) output (b) input (c) process
34. 34.💡 In a series circuit, how many paths does the current have? (a) one for each bulb (b) two (c) one (d) none
35. 35.True or false: a toggle switch flips up or down. (a) True (b) False
36. 36.What does an LDR do? (a) boosts a small signal (b) smooths a wobbly supply (c) glows using little power (d) senses how bright it is
37. 37.🔍 Which is the odd one out? (a) close the fridge quickly (b) leave the TV on standby (c) iron one shirt at a time (d) run fans in empty rooms
38. 38.🤖 if (distance < 10) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 1 cm. What happens? (a) buzzer is silent (b) buzzer beeps
39. 39.🔺 A 12 V supply is joined across a 300 Ω resistor. What current flows (in milliamperes, mA)?
40. 40.True or false: to set up with a parent is a risky habit. (a) False (b) True

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