Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 813 · 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.⏱️ 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
2. 2.Which of these is an output? (a) a keypad (b) a water pump (c) a light sensor (d) a turning knob
3. 3.🔦 A circuit has a new cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a ceramic cup. Does the bulb glow? (a) No (b) Yes
4. 4.What does a push button do? (a) closes when tipped over (b) springs back when let go (c) flips up or down (d) stays where you flip it
5. 5.🔺 A 1.6 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
6. 6.🌐 A weather station sends one reading every 15 seconds. How many readings does it send in 1 minute?
7. 7.🔘 Switch A is on the main wire next to the cell and the bulb; then the wire splits into two side-by-side paths, one with switch B and one with switch C. A is ON, B is OFF and C is ON. Does the bulb glow? (a) Yes (b) No
8. 8.🌐 A weather station sends one reading every 60 seconds. How many readings does it send in 2 minutes?
9. 9.🌐 Each reading a sensor sends is 25 bytes. How many bytes do 20 readings take?
10. 10.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
11. 11.🔺 A current of 0.1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
12. 12.True or false: “one bulb out, all go out” is true of a parallel circuit. (a) True (b) False
13. 13.🔺 A current of 10 mA flows when 3.3 V is joined across a resistor. What is its resistance (in ohms)?
14. 14.What does a transistor do? (a) stores a little charge (b) boosts a small signal (c) glows using little power (d) senses how hot it is
15. 15.🔁 Is the circuit closed or open if a wire has come loose? (a) closed (b) open
16. 16.✏️ In a circuit diagram, wires are usually drawn as … (a) little stars (b) wavy lines (c) straight lines (d) dotted circles
17. 17.⏱️ loop forever { LED ON; wait 100 ms; LED OFF; wait 400 ms }
    How many times does the LED blink in 7 seconds?
18. 18.True or false: to read app permissions is a risky habit. (a) True (b) False
19. 19.Which of these means the circuit is open? (a) the switch is ON (b) the bulb is unscrewed (c) all wires are joined (d) the loop is complete
20. 20.True or false: a motor turns a fan or wheels. (a) False (b) True
21. 21.🔐 Is it a good or a risky habit to install software updates? (a) risky habit (b) good habit
22. 22.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) an open circuit (b) a safe circuit (c) a parallel circuit (d) a short circuit
23. 23.🔋 On a cell, does “the shorter symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
24. 24.⚡ A 6 W device works on 3 V. What current does it take (in amperes)? =
25. 25.🔍 Which is the odd one out? (a) a Wi-Fi doorbell camera (b) a pencil sharpener (c) a plain table fan (d) a wind-up clock
26. 26.⚡ What do we call a flow of electric charge through a wire? (a) a magnet (b) friction (c) sound (d) electric current
27. 27.🔺 A current of 0.1 A flows through a 4 Ω resistor. What is the voltage across it (in volts)? =
28. 28.💡 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) dimmer (c) the same
29. 29.⏱️ loop forever { LED ON; wait 200 ms; LED OFF; wait 300 ms }
    How many times does the LED blink in 7 seconds?
30. 30.📏 How many amperes (A) is 700 mA? =
31. 31.🔺 A current of 25 mA flows when 7.5 V is joined across a resistor. What is its resistance (in ohms)?
32. 32.🧮 Adding another resistor in series makes the total resistance … (a) zero (b) smaller (c) bigger (d) stay the same
33. 33.What does a buzzer do? (a) senses how hot it is (b) has coloured bands (c) beeps for an alarm (d) lets current go one way
34. 34.Which job is done by the power LED? (a) shows the board is on (b) runs the program (c) connect sensors and LEDs (d) brings power and code
35. 35.🔍 For a microcontroller, is a sensor an input or an output? (a) an input (b) a power source (c) an output (d) a fuse
36. 36.🔋 What is a battery? (a) a switch with a lid (b) a kind of bulb (c) two or more cells joined (d) one single wire
37. 37.💡 2 identical bulbs are in parallel and each one takes 0.1 A. What total current (in amperes) comes from the battery? =
38. 38.💡 What does LED stand for? (a) low energy device (b) light energy dial (c) light-emitting diode (d) large electric dial
39. 39.True or false: if the switch is OFF, the circuit is closed and current flows. (a) False (b) True
40. 40.True or false: an electric iron mainly gives out heat. (a) False (b) True

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