Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 708 · 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.🔍 Which is the odd one out? (a) the pump turns on (b) a buzzer beeps (c) the fan starts (d) compare with a limit
2. 2.True or false: a circle with a cross is the symbol for a bulb. (a) True (b) False
3. 3.📶 Digital or analog: a knob turned part way? (a) digital (b) analog
4. 4.⚡ What does a siren mainly change electricity into? (a) heat (b) movement (c) sound (d) light
5. 5.✏️ In a circuit diagram, which part is drawn as one tall, one short bar? (a) switch (b) voltmeter (c) motor (d) cell
6. 6.📏 How many amperes (A) is 1940 mA? =
7. 7.True or false: “a single current path” is true of a series circuit. (a) True (b) False
8. 8.💡 In a series circuit, how many paths does the current have? (a) two (b) one (c) none (d) one for each bulb
9. 9.🔗 Series or parallel circuit: “each gets the full volts”? (a) parallel (b) series
10. 10.📶 Digital or analog: a tilt switch: on or off? (a) analog (b) digital
11. 11.🔁 x = 1
    repeat 3 times { x = x × 2 }
    What is x at the end?
12. 12.🔺 A current of 0.5 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔺 A current of 0.1 A flows when 1.5 V is joined across a resistor. What is its resistance (in ohms)?
14. 14.🔘 When a switch is ON, the circuit is … (a) open (b) cut (c) closed (d) broken
15. 15.⚠️ Is it safe to fly a kite near wires? (a) safe (b) not safe
16. 16.💡 What does LED stand for? (a) light-emitting diode (b) light energy dial (c) large electric dial (d) low energy device
17. 17.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 7 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
18. 18.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
19. 19.🔋 4 identical 2 V cells are joined in series (+ of one cell to − of the next). What is the total voltage (in volts)? =
20. 20.🔍 An object is 102 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
21. 21.💡 What happens if an LED is put in backwards? (a) it does not light (b) it lights brighter (c) it changes colour (d) it makes a sound
22. 22.True or false: “an LED lights up” is the input. (a) False (b) True
23. 23.True or false: on an LED, the shorter leg is the cathode (−). (a) True (b) False
24. 24.Which of these is a risky habit? (a) change default passwords (b) share camera links (c) turn off unused gadgets (d) cover unused cameras
25. 25.🧮 A 1.1 V battery is joined to 8 Ω and 3 Ω resistors in series. What current flows (in amperes)? =
26. 26.💡 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
27. 27.🔺 A current of 2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
28. 28.⚠️ Is it safe to dry your hands first? (a) safe (b) not safe
29. 29.💡 Why does an LED need a resistor in series? (a) to store charge (b) to change its colour (c) to make it brighter (d) to limit the current
30. 30.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 24) { show “Warm” } else { show “Cool” }
    The temperature is 14 °C. What is shown? (a) Hot (b) Warm (c) Cool
31. 31.True or false: two or more cell symbols is the symbol for a diode. (a) False (b) True
32. 32.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark a 120 Ω resistor? (a) red-brown-brown (b) brown-red-brown (c) brown-red-red (d) brown-red-black
33. 33.🔁 total = 0
    for i = 1 to 7 { total = total + i }
    What is total at the end?
34. 34.🔋 Does a washing machine give electricity or use electricity? (a) gives electricity (b) uses electricity
35. 35.🔁 count = 1
    while (count < 41) { count = count + 5 }
    How many times does the loop run?
36. 36.🔺 A current of 0.2 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
37. 37.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. Bulb 2 is taken out of its holder. How many bulbs glow?
38. 38.🔋 What should you do with used-up cells? (a) cut them open (b) throw them in a fire (c) give them for recycling (d) bury them in soil
39. 39.📏 Which unit measures current? (a) watt (W) (b) ohm (Ω) (c) volt (V) (d) ampere (A)
40. 40.🔘 Two switches are in series. When does the bulb glow? (a) when either is ON (b) never (c) when both are ON (d) when both are OFF

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