Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 318 · 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 resistor has the colour bands violet, black, brown. What is its value (in ohms)?
2. 2.🔺 A current of 2.5 A flows through a 15 Ω resistor. What is the voltage across it (in volts)? =
3. 3.Which of these is true of a series circuit? (a) one out, the rest glow (b) many paths for current (c) used in house wiring (d) one bulb out, all go out
4. 4.⏱️ repeat 9 times { buzzer ON; wait 100 ms; buzzer OFF; wait 200 ms }
   How many milliseconds does this take in all?
5. 5.🔋 What is a battery? (a) a kind of bulb (b) a switch with a lid (c) two or more cells joined (d) one single wire
6. 6.Which of these means the circuit is closed? (a) the switch is OFF (b) the bulb is unscrewed (c) the loop is complete (d) a wire is cut
7. 7.⏱️ What does “wait 500 ms” do? (a) waits 500 seconds (b) blinks 500 times (c) turns the LED off (d) pauses for half a second
8. 8.Which of these wastes electricity? (a) leave fridge door open (b) switch off empty rooms (c) use daylight to read (d) close the fridge quickly
9. 9.📏 How many amperes (A) is 1130 mA? =
10. 10.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = R ÷ V (c) I = V + R (d) I = V × R
11. 11.⏱️ loop forever { LED ON; wait 250 ms; LED OFF; wait 250 ms }
    How many times does the LED blink in 7 seconds?
12. 12.True or false: “each gets the full volts” is true of a parallel circuit. (a) False (b) True
13. 13.🔺 A current of 50 mA flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
14. 14.🤖 if (temperature > 30) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 29 °C. What is shown? (a) Warm (b) Hot (c) Cool
15. 15.🔘 Two switches are in series. When does the bulb glow? (a) when both are OFF (b) when both are ON (c) never (d) when either is ON
16. 16.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
17. 17.🔌 Why are electric wires covered in plastic? (a) plastic makes current (b) plastic is an insulator (c) to make them heavy (d) plastic is a conductor
18. 18.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) prints 1 (d) takes 1 away
19. 19.🌈 Which band is read first on a resistor? (a) the widest gap (b) any band (c) the gold band (d) the one nearest an end
20. 20.✏️ Why do engineers draw circuits with symbols? (a) quick and clear for all (b) symbols are heavier (c) to make it colourful (d) to hide the circuit
21. 21.🔘 Which kind of switch flips up or down? (a) a slide switch (b) a push button (c) a toggle switch (d) a tilt switch
22. 22.⚡ A home appliance on the 230 V mains takes 5 A. What is its power (in watts)?
23. 23.True or false: “bulbs share the voltage” is true of a series circuit. (a) True (b) False
24. 24.🤖 “if (A AND B)” is true when … (a) only A is true (b) both are false (c) both A and B are true (d) only B is true
25. 25.🔺 A 1.2 V supply is joined across a 6 Ω resistor. What current flows (in amperes)? =
26. 26.What does an LED do? (a) is a resistance knob (b) lets current go one way (c) makes a beeping sound (d) glows using little power
27. 27.⚙️ What is an actuator? (a) a program (b) a battery (c) an output that acts (d) a sensor
28. 28.⚡ A 9 W device works on 9 V. What current does it take (in amperes)? =
29. 29.🔁 count = 5
    repeat 4 times { count = count + 9 }
    What is count at the end?
30. 30.🔺 A current of 25 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they keep glowing (c) they explode (d) they all go out
32. 32.🤖 Does a wind-up toy usually have a microcontroller inside? (a) No (b) Yes
33. 33.True or false: a slide switch stays where you flip it. (a) False (b) True
34. 34.True or false: a tube light mainly makes movement. (a) True (b) False
35. 35.What does a capacitor do? (a) blows if current is high (b) beeps for an alarm (c) has coloured bands (d) stores a little charge
36. 36.🌈 A resistor has the colour bands blue, brown, orange. What is its value (in ohms)?
37. 37.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in series (d) in parallel
38. 38.True or false: on a cell, “the end with a bump” means the + (positive) end. (a) True (b) False
39. 39.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 4 hours?
40. 40.📏 How many amperes (A) is 1580 mA? =

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