Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 766 · 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: a buzzer beeps for an alarm. (a) True (b) False
2. 2.🔍 Which is the odd one out? (a) climb an electric pole (b) keep drinks far away (c) touch a switch when wet (d) fly a kite near wires
3. 3.🗺️ Before building a project, what should you write down first? (a) nothing at all (b) inputs and outputs (c) the box colour (d) the final price
4. 4.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) + (positive) (b) − (negative)
5. 5.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a safe circuit (b) an open circuit (c) a parallel circuit (d) a short circuit
6. 6.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 87 Ω resistor? (a) white-violet-black (b) grey-violet-black (c) violet-grey-black (d) grey-violet-brown
7. 7.🔺 In the V-I-R triangle, how do we find I? (a) I = V + R (b) I = V × R (c) I = V ÷ R (d) I = R ÷ V
8. 8.True or false: to use small battery cells is not safe. (a) False (b) True
9. 9.⚠️ Is it safe to fly a kite near wires? (a) not safe (b) safe
10. 10.🔘 Which kind of switch stays where you flip it? (a) a push button (b) a reed switch (c) a slide switch (d) a toggle switch
11. 11.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is ON and B is ON. Does the bulb glow? (a) No (b) Yes
12. 12.🤖 if (light < 400 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 220 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
13. 13.True or false: “a temperature reading” is the input. (a) True (b) False
14. 14.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
15. 15.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) in series (c) in parallel (d) not joined
16. 16.Which of these is safe? (a) take cells out after use (b) climb an electric pole (c) fly a kite near wires (d) use mains for a project
17. 17.🔋 7 identical 1.5 V cells are joined in series, but one of them is put in the wrong way round. What is the total voltage now (in volts)? =
18. 18.🔍 Which is the odd one out? (a) a metal paper clip (b) a copper wire (c) a woollen thread (d) an iron nail
19. 19.🔺 A 25 V supply is joined across a 10 Ω resistor. What current flows (in amperes)? =
20. 20.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) gets bigger (b) becomes zero (c) stays the same (d) gets smaller
21. 21.🤖 if (temperature > 28) { fan ON } else { fan OFF }
    The temperature sensor reads 22 °C. What happens? (a) fan OFF (b) fan ON
22. 22.💡 On an LED, is the leg by the flat edge the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
23. 23.🔦 A circuit has a new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) Yes (b) No
24. 24.🔁 x = 1
    repeat 1 time { x = x × 2 }
    What is x at the end?
25. 25.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
26. 26.Which of these is true of a series circuit? (a) one out, the rest glow (b) each gets the full volts (c) many paths for current (d) one bulb out, all go out
27. 27.🔐 Is it a good or a risky habit to share the Wi-Fi key? (a) risky habit (b) good habit
28. 28.🔋 Does a mobile phone give electricity or use electricity? (a) gives electricity (b) uses electricity
29. 29.What does an LDR do? (a) senses how bright it is (b) blows if current is high (c) limits the current (d) turns a fan or wheels
30. 30.🔁 total = 0
    for i = 1 to 9 { total = total + i }
    What is total at the end?
31. 31.🌈 A resistor has the colour bands green, violet, red. What is its value (in ohms)?
32. 32.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) it starts again (c) it deletes itself (d) the board breaks
33. 33.🤖 if (distance < 15) { buzzer beeps } else { buzzer is silent }
    The distance sensor reads 7 cm. What happens? (a) buzzer is silent (b) buzzer beeps
34. 34.🧮 Two resistors in parallel give a total that is … (a) always zero (b) more than either one (c) their sum (d) less than either one
35. 35.⚡ A home appliance on the 230 V mains takes 1.5 A. What is its power (in watts)?
36. 36.⚡ What does a street light mainly change electricity into? (a) movement (b) heat (c) sound (d) light
37. 37.🔁 repeat 6 times { repeat 2 times { beep } }
    How many beeps are there?
38. 38.📏 How many amperes (A) is 2350 mA? =
39. 39.🤖 if (moisture < 30) { pump ON } else { pump OFF }
    The soil moisture sensor reads 22 %. What happens? (a) pump ON (b) pump OFF
40. 40.🔺 A current of 40 mA flows through a 220 Ω resistor. What is the voltage across it (in volts)? =

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