Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 771 · 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: an electric drill mainly gives out light. (a) True (b) False
2. 2.⚡ Which formula gives electric power? (a) P = V + I (b) P = V × I (c) P = V ÷ I (d) P = I ÷ V
3. 3.🔐 Is it a good or a risky habit to share only needed data? (a) risky habit (b) good habit
4. 4.🌈 Which colour bands (1st digit, 2nd digit, multiplier) mark an 89 Ω resistor? (a) grey-white-brown (b) white-grey-black (c) grey-white-black (d) white-white-black
5. 5.🗺️ In an input → process → output plan, is “a buzzer beeps” the input, the process or the output? (a) output (b) process (c) input
6. 6.⚡ A device works on 3 V and takes 1 A. What is its power (in watts)? =
7. 7.What does an LED do? (a) turns a fan or wheels (b) smooths a wobbly supply (c) glows using little power (d) blows if current is high
8. 8.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
9. 9.📶 Digital or analog: the room temperature? (a) analog (b) digital
10. 10.🤖 Microcontroller or laptop: which one has a built-in keyboard? (a) microcontroller (b) laptop
11. 11.🔺 A current of 20 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
12. 12.What does a reed switch do? (a) closes when tipped over (b) springs back when let go (c) closes near a magnet (d) flips up or down
13. 13.💡 A red LED uses 2 V and should get 10 mA. It runs from a 9 V supply. What resistor (in ohms) is needed in series?
14. 14.💡 2 identical bulbs are joined in series with a battery and a closed switch on the main wire. All the bulbs are in place. Does bulb 2 glow? (a) Yes (b) No
15. 15.🔘 A cell, a bulb and switches A, B and C are joined one after another in a single loop (series). A is OFF, B is ON and C is OFF. Does the bulb glow? (a) Yes (b) No
16. 16.⚙️ What is an actuator? (a) an output that acts (b) a program (c) a battery (d) a sensor
17. 17.True or false: an electric drill mainly makes movement. (a) True (b) False
18. 18.🔋 How many volts does one ordinary torch cell give? (a) 15 V (b) 230 V (c) 1.5 V (d) 0.5 V
19. 19.Which of these is safe? (a) use mains for a project (b) touch a fallen wire (c) dry your hands first (d) touch a switch when wet
20. 20.🔺 A current of 0.2 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
21. 21.🔺 A current of 50 mA flows through a 500 Ω resistor. What is the voltage across it (in volts)? =
22. 22.🧮 Adding another resistor in series makes the total resistance … (a) stay the same (b) bigger (c) smaller (d) zero
23. 23.🔘 Which kind of switch works only while pressed? (a) a tilt switch (b) a slide switch (c) a reed switch (d) a push button
24. 24.🗺️ In an input → process → output plan, is “check if temp > 30” the input, the process or the output? (a) process (b) output (c) input
25. 25.True or false: the ammeter is joined across a part. (a) True (b) False
26. 26.🔋 3 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)? =
27. 27.🔘 A cell and a bulb are joined to two side-by-side paths: path 1 has switches A and B one after another, path 2 has switch C. A is OFF, B is ON and C is OFF. Does the bulb glow? (a) No (b) Yes
28. 28.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a dry cork across the gap. Does the bulb glow? (a) Yes (b) No
29. 29.⏱️ A program says “wait 8250 ms”. How many seconds is that? =
30. 30.🔺 A current of 0.1 A flows when 1 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.🔘 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
32. 32.💡 Why does an LED need a resistor in series? (a) to make it brighter (b) to change its colour (c) to limit the current (d) to store charge
33. 33.🔁 x = 5
    repeat 3 times { x = x × 2 }
    What is x at the end?
34. 34.True or false: a graphite rod is an insulator. (a) True (b) False
35. 35.🔢 To get a sensor reading onto a phone, which is the FIRST step? (a) it is sent by Wi-Fi (b) the board reads it (c) the sensor measures (d) the cloud stores it
36. 36.⚠️ A cell gets hot when its + and − ends are joined by a bare wire. What is this called? (a) a parallel circuit (b) an open circuit (c) a safe circuit (d) a short circuit
37. 37.📶 How many states can a digital pin have? (a) two (b) a thousand (c) ten (d) one
38. 38.⏱️ loop forever { LED ON; wait 150 ms; LED OFF; wait 850 ms }
    How many milliseconds does one blink (ON + OFF) take?
39. 39.🔍 Which is the odd one out? (a) a wooden stick (b) a woollen thread (c) a metal paper clip (d) a plastic ruler
40. 40.🔍 Which is the odd one out? (a) a wind-up clock (b) a Wi-Fi smart plug (c) a Wi-Fi doorbell camera (d) an app-controlled bulb

Free electronics lessons, practice and worksheets at talentjr.in/electronics-for-kids