Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 799 · 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 24 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
2. 2.🔁 total = 0
   for i = 1 to 3 { total = total + i }
   What is total at the end?
3. 3.💡 In a series circuit, how many paths does the current have? (a) one (b) none (c) one for each bulb (d) two
4. 4.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) becomes zero (b) gets smaller (c) gets bigger (d) stays the same
5. 5.✏️ In a circuit diagram, which part is drawn as a plain rectangle? (a) battery (b) cell (c) resistor (d) junction
6. 6.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = V × I (c) R = I ÷ V (d) R = V + I
7. 7.🔁 What does “count = count + 1” do? (a) prints 1 (b) adds 1 to count (c) takes 1 away (d) sets count to 1
8. 8.🔍 Which is the odd one out? (a) a glass marble (b) an iron nail (c) a copper wire (d) a brass key
9. 9.⏱️ A program says “wait 750 ms”. How many seconds is that? =
10. 10.💡 On an LED, is the shorter leg the anode (+) or the cathode (−)? (a) cathode (−) (b) anode (+)
11. 11.Which of these wastes electricity? (a) use daylight to read (b) switch off empty rooms (c) use old filament bulbs (d) set the AC to 24 °C
12. 12.✏️ In a circuit diagram, which part is drawn as two or more cell symbols? (a) switch (b) battery (c) resistor (d) diode
13. 13.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) zero (c) bigger (d) smaller
14. 14.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 2 hours?
15. 15.🧮 A 3.5 V battery is joined to 10 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
16. 16.🌐 Is a Wi-Fi doorbell camera an IoT device? (a) not an IoT device (b) an IoT device
17. 17.True or false: “bulbs share the voltage” is true of a series circuit. (a) False (b) True
18. 18.🧩 Which component is a resistance knob? (a) thermistor (b) diode (c) capacitor (d) potentiometer
19. 19.🧮 An 11 V battery is joined to 6 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
20. 20.🔘 Which kind of switch flips up or down? (a) a slide switch (b) a push button (c) a reed switch (d) a toggle switch
21. 21.🔁 What does a variable do in a program? (a) blinks an LED (b) stores a value (c) measures light (d) joins two wires
22. 22.True or false: “how loud a sound is” is a digital signal. (a) False (b) True
23. 23.⚡ What does an LED lamp mainly change electricity into? (a) movement (b) light (c) sound (d) heat
24. 24.🔘 Two switches are in parallel (side by side). When does the bulb glow? (a) when either is ON (b) only when both are OFF (c) only when both are ON (d) never
25. 25.Which of these is the input? (a) the fan starts (b) an alert on the phone (c) an LED lights up (d) a motion sensor signal
26. 26.🔍 Which is the odd one out? (a) a temperature reading (b) the fan starts (c) the pump turns on (d) an alert on the phone
27. 27.True or false: a circle with a cross is the symbol for a motor. (a) True (b) False
28. 28.🔺 An 8.8 V supply is joined across a 220 Ω resistor. What current flows (in milliamperes, mA)?
29. 29.💡 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
    Is the LED ON or OFF at the end? (a) OFF (b) ON
30. 30.⚡ What does an electric drill mainly change electricity into? (a) heat (b) sound (c) light (d) movement
31. 31.🔁 count = 1
    while (count < 36) { count = count + 5 }
    How many times does the loop run?
32. 32.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 1000 (d) 60
33. 33.💡 4 identical bulbs are joined in parallel across a 6 V battery (ideal wires). How many volts does each bulb get? =
34. 34.True or false: a ceramic cup is a conductor. (a) False (b) True
35. 35.⚡ A device works on 9 V and takes 0.2 A. What is its power (in watts)? =
36. 36.Which of these mainly makes sound? (a) a buzzer (b) a mixer grinder (c) a street light (d) an LED lamp
37. 37.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V × R (c) I = V + R (d) I = V ÷ R
38. 38.Which of these is a risky habit? (a) share only needed data (b) set a strong password (c) set up with a parent (d) reuse one password
39. 39.🧮 Four equal 100 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
40. 40.True or false: to fly a kite near wires is not safe. (a) True (b) False

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