Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 449 · 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: “HIGH or LOW only” is a digital signal. (a) True (b) False
2. 2.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
   The temperature is 39 °C. What is shown? (a) Hot (b) Warm (c) Cool
3. 3.Which of these is an output? (a) a motion sensor (b) a push button (c) a small display (d) a sound sensor
4. 4.📏 Which unit measures voltage? (a) volt (V) (b) ampere (A) (c) watt (W) (d) ohm (Ω)
5. 5.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 5 minutes?
6. 6.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
7. 7.🔍 Which is the odd one out? (a) a steel spoon (b) a metal paper clip (c) a brass key (d) a rubber band
8. 8.🔋 2 identical 3 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
9. 9.Which of these is an output? (a) a keypad (b) a servo motor (c) a light sensor (d) a temperature sensor
10. 10.🔐 Who should decide which smart devices go in a child’s room? (a) nobody at all (b) an online stranger (c) a parent or guardian (d) the app’s adverts
11. 11.Which of these is safe? (a) throw cells in a fire (b) use mains for a project (c) dry your hands first (d) touch a fallen wire
12. 12.🔍 Which is the odd one out? (a) a Wi-Fi smart plug (b) an app-controlled bulb (c) a Wi-Fi doorbell camera (d) a plain wall switch
13. 13.🔍 Which is the odd one out? (a) use mains for a project (b) use a cable with cuts (c) poke things in a socket (d) dry your hands first
14. 14.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a wooden stick across the gap. Does the bulb glow? (a) Yes (b) No
15. 15.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 4 minutes?
16. 16.🧮 A 1 V battery is joined to 4 Ω and 6 Ω resistors in series. What current flows (in amperes)? =
17. 17.🤖 if (sound > 80) { red LED ON } else { green LED ON }
    The sound sensor reads 73. What happens? (a) green LED ON (b) red LED ON
18. 18.True or false: a plastic ruler is a conductor. (a) False (b) True
19. 19.True or false: a plain rectangle is the symbol for a capacitor. (a) False (b) True
20. 20.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V + I (c) R = V × I (d) R = I ÷ V
21. 21.📶 Digital or analog: HIGH or LOW only? (a) digital (b) analog
22. 22.True or false: the voltmeter measures current. (a) True (b) False
23. 23.True or false: a potentiometer glows using little power. (a) True (b) False
24. 24.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 8 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
25. 25.🔍 Which is the odd one out? (a) tap unknown app links (b) set a strong password (c) log out of shared phones (d) share only needed data
26. 26.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
    The temperature is 10 °C. What is shown? (a) Cool (b) Hot (c) Warm
27. 27.🔌 Which metal is used for most electric wires at home? (a) glass (b) copper (c) plastic (d) rubber
28. 28.🔺 In the V-I-R triangle, how do we find V? (a) V = I + R (b) V = I ÷ R (c) V = I × R (d) V = R ÷ I
29. 29.🔺 A current of 1.5 A flows when 30 V is joined across a resistor. What is its resistance (in ohms)?
30. 30.⚠️ Who should be with you when you build a circuit? (a) a stranger online (b) a younger child (c) nobody (d) a trusted adult
31. 31.True or false: many long-short pairs is the symbol for a battery. (a) False (b) True
32. 32.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
33. 33.🔁 x = 5
    repeat 2 times { x = x × 2 }
    What is x at the end?
34. 34.🤖 When the main loop of a microcontroller program ends, what happens? (a) it deletes itself (b) it starts again (c) it stops forever (d) the board breaks
35. 35.What does the sensor do? (a) stores data online (b) carries the data (c) acts on a command (d) measures the real world
36. 36.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 21 cm. What happens? (a) buzzer beeps (b) buzzer is silent
37. 37.🔘 A bulb and a cell are joined through 4 switches one after another in a single loop (series). What is the smallest number of switches that must be ON to light the bulb?
38. 38.💡 4 identical bulbs are in parallel and each bulb has its own switch on its path. 3 of the switches are OFF and the rest are ON. How many bulbs glow?
39. 39.💡 3 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 3 is taken out of its holder. Does bulb 2 glow? (a) Yes (b) No
40. 40.💡 4 identical bulbs are in parallel and each one takes 0.2 A. What total current (in amperes) comes from the battery? =

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