Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 201 · 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.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they explode (c) they keep glowing (d) they get dimmer
2. 2.True or false: the voltmeter is joined in series. (a) False (b) True
3. 3.🔍 A distance sensor sends a sound pulse and hears the echo 3 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
4. 4.🔍 Which is the odd one out? (a) a steel spoon (b) a cotton thread (c) a metal paper clip (d) an iron nail
5. 5.True or false: “a motion sensor signal” is the output. (a) False (b) True
6. 6.🔋 A 3 V battery and four 1.5 V cells are joined in series, all facing the same way. What is the total voltage (in volts)? =
7. 7.🔌 Is a dry cork a conductor or an insulator? (a) a conductor (b) an insulator
8. 8.🔺 A current of 40 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
9. 9.🔘 Which kind of switch flips up or down? (a) a toggle switch (b) a reed switch (c) a tilt switch (d) a push button
10. 10.🧭 Which part of a microcontroller board runs the program? (a) the power LED (b) the reset button (c) the pins (d) the main chip
11. 11.🔺 A current of 10 mA flows through a 300 Ω resistor. What is the voltage across it (in volts)? =
12. 12.🔺 A current of 25 mA flows through a 200 Ω resistor. What is the voltage across it (in volts)? =
13. 13.🔺 The voltage stays the same and the resistance gets bigger. The current … (a) stays the same (b) becomes zero (c) gets bigger (d) gets smaller
14. 14.⏱️ loop forever { LED ON; wait 650 ms; LED OFF; wait 50 ms }
    How many milliseconds does one blink (ON + OFF) take?
15. 15.🔺 A current of 25 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
17. 17.🔺 A 30 V supply is joined across a 15 Ω resistor. What current flows (in amperes)? =
18. 18.🔍 Which sensor would you use to stop a robot near walls? (a) a gas sensor (b) a distance sensor (c) a temperature sensor (d) a light sensor
19. 19.💡 6 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 1 is taken out of its holder. How many bulbs glow?
20. 20.Which drawing is the symbol for an ammeter? (a) a straight line (b) a small empty box (c) a circle with a cross (d) a circle with A inside
21. 21.🧮 A 2.25 V battery is joined to 4 Ω and 5 Ω resistors in series. What current flows (in amperes)? =
22. 22.Which drawing is the symbol for a voltmeter? (a) triangle, bar and arrows (b) triangle against a bar (c) a circle with V inside (d) two equal parallel lines
23. 23.Which of these usually has a microcontroller inside? (a) a wind-up toy (b) a candle (c) a bicycle bell (d) a washing machine
24. 24.🤖 Does a digital thermometer usually have a microcontroller inside? (a) No (b) Yes
25. 25.🔁 What do we call a circuit with a break in it? (a) a closed circuit (b) a full circuit (c) an open circuit (d) a series circuit
26. 26.⚡ A 7.5 W device works on 5 V. What current does it take (in amperes)? =
27. 27.🔁 total = 0
    for i = 1 to 9 { total = total + i }
    What is total at the end?
28. 28.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 50 % (c) 25 % (d) 0 %
29. 29.🔋 8 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)? =
30. 30.🤖 Where does the board keep its program when the power is off? (a) the USB cable (b) flash memory (c) the resistor (d) the power LED
31. 31.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
32. 32.🌐 In an IoT system, which part carries the data? (a) Wi-Fi (b) phone app (c) actuator (d) cloud server
33. 33.🔦 A circuit has a new cell, a good bulb and a switch that is ON. One wire has come loose from the cell. A gap in one wire is bridged by a steel spoon. Does the bulb glow? (a) Yes (b) No
34. 34.🧮 Resistors of 22 Ω, 470 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
35. 35.🔺 A current of 1.5 A flows through an 8 Ω resistor. What is the voltage across it (in volts)? =
36. 36.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) dimmer (b) the same (c) brighter
37. 37.True or false: to post your live location is a good habit. (a) True (b) False
38. 38.Which of these is an input? (a) a buzzer (b) a small display (c) an LED (d) a sound sensor
39. 39.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to hide the circuit (c) to make it colourful (d) quick and clear for all
40. 40.Which of these is an output? (a) a sound sensor (b) a keypad (c) a servo motor (d) a light sensor

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