Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 203 · 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: to stop a robot near walls, use a sound sensor. (a) True (b) False
2. 2.⚡ What does a buzzer mainly change electricity into? (a) light (b) sound (c) heat (d) movement
3. 3.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V + R (c) I = R ÷ V (d) I = V × R
4. 4.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
   set pin 8 HIGH
   set pin 7 HIGH
   Is the LED ON or OFF at the end? (a) OFF (b) ON
5. 5.🗺️ In an input → process → output plan, is “an alert on the phone” the input, the process or the output? (a) input (b) output (c) process
6. 6.What does the phone app do? (a) shows data to you (b) measures the real world (c) carries the data (d) acts on a command
7. 7.What does a motor do? (a) is a resistance knob (b) senses how bright it is (c) makes things spin (d) lets current go one way
8. 8.💡 A battery lights 2 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) the same (b) dimmer (c) brighter
9. 9.🔁 What does a variable do in a program? (a) joins two wires (b) measures light (c) blinks an LED (d) stores a value
10. 10.🔢 To run one loop of a plant-watering program, what comes right after “switch the pump on/off”? (a) wait a few seconds (b) compare with the limit (c) read the soil sensor
11. 11.🔐 Privacy for a smart device means controlling … (a) its battery size (b) who can see your data (c) how loud it beeps (d) its colour
12. 12.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) zero (d) smaller
13. 13.True or false: two equal parallel lines is the symbol for a battery. (a) False (b) True
14. 14.🔁 total = 0
    for i = 1 to 6 { total = total + i }
    What is total at the end?
15. 15.🔍 Which is the odd one out? (a) a plain wall switch (b) a paper calendar (c) a Wi-Fi weather station (d) a wind-up clock
16. 16.📶 On a 5 V board, a pin set HIGH gives about … (a) 50 V (b) 230 V (c) 0 V (d) 5 V
17. 17.🔁 x = 2
    repeat 5 times { x = x × 2 }
    What is x at the end?
18. 18.🤖 if (temperature > 33) { show “Hot” } else if (temperature > 19) { show “Warm” } else { show “Cool” }
    The temperature is 13 °C. What is shown? (a) Hot (b) Warm (c) Cool
19. 19.True or false: to stop if a part gets hot is not safe. (a) True (b) False
20. 20.🔁 Is the circuit closed or open if all wires are joined? (a) open (b) closed
21. 21.🔍 A distance sensor sends a sound pulse and hears the echo 17 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
22. 22.Which of these means the circuit is closed? (a) a cell is taken out (b) the bulb is unscrewed (c) the switch is OFF (d) all wires are joined
23. 23.🧮 A 2 V battery is joined to 8 Ω and 12 Ω resistors in series. What current flows (in amperes)? =
24. 24.🔌 Is an iron nail a conductor or an insulator? (a) an insulator (b) a conductor
25. 25.🔋 How many 3 V cells must be joined in series to give 18 V?
26. 26.🤖 if (light < 200) { lamp ON } else { lamp OFF }
    The light sensor reads 109. What happens? (a) lamp OFF (b) lamp ON
27. 27.Which of these is true of a parallel circuit? (a) a single current path (b) used in house wiring (c) a break stops every bulb (d) bulbs share the voltage
28. 28.Which of these is true of a parallel circuit? (a) a break stops every bulb (b) a single current path (c) bulbs share the voltage (d) own switch for each bulb
29. 29.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 810 Ω resistor? (a) grey-brown-red (b) grey-brown-black (c) grey-brown-brown (d) brown-grey-brown
30. 30.🔍 Which is the odd one out? (a) a sound sensor (b) a keypad (c) an LED (d) a temperature sensor
31. 31.🔺 A current of 10 mA flows through a 100 Ω resistor. What is the voltage across it (in volts)? =
32. 32.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 160 readings take?
33. 33.💡 Why is house wiring done in parallel? (a) to make bulbs dim (b) so all go off together (c) each gets full voltage (d) to save copper only
34. 34.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a plastic ruler. Does the bulb glow? (a) Yes (b) No
35. 35.🔌 Is a push button an input or an output for a microcontroller? (a) input (b) output
36. 36.🤖 if (light < 400) { lamp ON } else { lamp OFF }
    The light sensor reads 324. What happens? (a) lamp ON (b) lamp OFF
37. 37.True or false: a steel spoon is an insulator. (a) True (b) False
38. 38.Which of these is an insulator? (a) a copper wire (b) a safety pin (c) a graphite rod (d) a plastic ruler
39. 39.🔌 Most metals are good … (a) batteries (b) magnets only (c) insulators (d) conductors
40. 40.⚡ A device works on 1.5 V and takes 0.5 A. What is its power (in watts)? =

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