Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 959 · 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.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
2. 2.⏱️ repeat 9 times { buzzer ON; wait 200 ms; buzzer OFF; wait 500 ms }
   How many milliseconds does this take in all?
3. 3.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 780 Ω resistor? (a) violet-grey-black (b) violet-grey-brown (c) violet-grey-red (d) grey-violet-brown
4. 4.💡 5 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
5. 5.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) to hide the circuit (d) quick and clear for all
6. 6.🔌 Is an iron nail a conductor or an insulator? (a) an insulator (b) a conductor
7. 7.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) process (b) input (c) output
8. 8.🗺️ In an input → process → output plan, is “the pump turns on” the input, the process or the output? (a) process (b) output (c) input
9. 9.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 73 Ω resistor? (a) orange-violet-black (b) violet-orange-brown (c) grey-orange-black (d) violet-orange-black
10. 10.🧮 A 150 Ω resistor is joined in series with two equal 200 Ω resistors that are in parallel with each other. What is the total resistance (in ohms)?
11. 11.🔘 Which kind of switch works only while pressed? (a) a push button (b) a slide switch (c) a reed switch (d) a tilt switch
12. 12.Which of these gives us electricity? (a) an air conditioner (b) a mobile phone (c) a generator (d) a washing machine
13. 13.⚡ What does a table fan mainly change electricity into? (a) movement (b) heat (c) sound (d) light
14. 14.💡 Why is house wiring done in parallel? (a) each gets full voltage (b) so all go off together (c) to save copper only (d) to make bulbs dim
15. 15.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
16. 16.Which of these is the input? (a) count button presses (b) a motion sensor signal (c) the pump turns on (d) decide if soil is dry
17. 17.🔋 A 6 V battery and two 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
18. 18.📶 Digital or analog: a knob turned part way? (a) analog (b) digital
19. 19.🧩 Which component smooths a wobbly supply? (a) buzzer (b) fuse (c) LDR (d) capacitor
20. 20.⚙️ Which actuator would you use to move water to plants? (a) a buzzer (b) an LED (c) a servo motor (d) a pump
21. 21.⚡ A 4.5 W device works on 1.5 V. What current does it take (in amperes)? =
22. 22.💡 6 identical bulbs are in parallel and each one takes 0.25 A. What total current (in amperes) comes from the battery? =
23. 23.🔍 Which is the odd one out? (a) take cells out after use (b) touch a fallen wire (c) throw cells in a fire (d) climb an electric pole
24. 24.Which of these is the process? (a) a temperature reading (b) a button press (c) a buzzer beeps (d) compare with a limit
25. 25.True or false: a toggle switch works only while pressed. (a) False (b) True
26. 26.🔍 A distance sensor sends a sound pulse and hears the echo 7 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
27. 27.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the reset button (b) the voltage regulator (c) the pins (d) the main chip
28. 28.🌐 In an IoT system, which part reads values, decides? (a) sensor (b) cloud server (c) microcontroller (d) Wi-Fi
29. 29.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
30. 30.🔋 How many 1.5 V cells must be joined in series to give 3 V?
31. 31.🤖 Where does the board keep its program when the power is off? (a) the power LED (b) the USB cable (c) the resistor (d) flash memory
32. 32.🗺️ In an input → process → output plan, is “a light level reading” the input, the process or the output? (a) input (b) output (c) process
33. 33.💡 In a series circuit, how many paths does the current have? (a) none (b) two (c) one for each bulb (d) one
34. 34.🔋 Does a cell give electricity or use electricity? (a) gives electricity (b) uses electricity
35. 35.🤖 In “if (temp > 30)”, what runs when temp is exactly 30? (a) neither part (b) both parts (c) the if part (d) the else part
36. 36.💡 5 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulbs 1 and 4 are taken out of their holders. How many bulbs glow?
37. 37.🔍 Which is the odd one out? (a) a toaster (b) a rice cooker (c) an electric kettle (d) a mixer grinder
38. 38.⏱️ A program says “wait 6000 ms”. How many seconds is that? =
39. 39.🔺 In the V-I-R triangle, how do we find R? (a) R = V + I (b) R = I ÷ V (c) R = V × I (d) R = V ÷ I
40. 40.🌈 A resistor has the colour bands red, grey, black. What is its value (in ohms)?

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