Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 882 · 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.Which of these is an output? (a) a push button (b) a keypad (c) an LED (d) a motion sensor
2. 2.Which of these is safe? (a) use a cable with cuts (b) open a phone charger (c) throw cells in a fire (d) build with an adult near
3. 3.Which job needs a buzzer? (a) move water to plants (b) spin a robot’s wheels (c) open a gate to 90° (d) beep an alarm
4. 4.🔍 For a microcontroller, is a sensor an input or an output? (a) a fuse (b) a power source (c) an output (d) an input
5. 5.⚡ Which formula gives electric power? (a) P = I ÷ V (b) P = V × I (c) P = V ÷ I (d) P = V + I
6. 6.True or false: an electric toy car mainly gives out light. (a) False (b) True
7. 7.True or false: voltage is measured in amperes (A). (a) False (b) True
8. 8.💡 A battery lights 5 identical bulbs joined in series. One more identical bulb is added in series. How do the bulbs glow now? (a) brighter (b) the same (c) dimmer
9. 9.💡 2 identical bulbs are joined in series with an 8 V battery (ideal wires). How many volts does each bulb get? =
10. 10.True or false: “one out, the rest glow” is true of a parallel circuit. (a) False (b) True
11. 11.Which job needs a motion sensor? (a) spot someone walking in (b) start a fan when hot (c) measure classroom noise (d) make a parking alarm
12. 12.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
13. 13.⚙️ Which actuator would you use to open a gate to 90°? (a) a motor (b) a pump (c) a buzzer (d) a servo motor
14. 14.🔢 To plan an electronics project, which is the LAST step? (a) test it and fix it (b) build it with an adult (c) pick a problem to solve (d) draw the circuit diagram
15. 15.🔺 A current of 50 mA flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🔗 Series or parallel circuit: “many paths for current”? (a) parallel (b) series
17. 17.🌈 A resistor has the colour bands red, green, yellow. What is its value in kilo-ohms (kΩ)? =
18. 18.🌐 A weather station sends one reading every 10 seconds. How many readings does it send in 8 minutes?
19. 19.🔺 In the V-I-R triangle, how do we find I? (a) I = R ÷ V (b) I = V ÷ R (c) I = V × R (d) I = V + R
20. 20.⏱️ How many milliseconds are in 1 second? (a) 60 (b) 10 (c) 100 (d) 1000
21. 21.🔺 A current of 1 A flows through a 20 Ω resistor. What is the voltage across it (in volts)? =
22. 22.🔢 To get a sensor reading onto a phone, what comes right after “it is sent by Wi-Fi”? (a) the board reads it (b) the cloud stores it (c) the app shows it (d) the sensor measures
23. 23.Which drawing is the symbol for a diode? (a) a circle with an X in it (b) a straight line (c) a dot where wires meet (d) triangle against a bar
24. 24.True or false: “used in house wiring” is true of a parallel circuit. (a) False (b) True
25. 25.🤖 if (temperature > 34) { show “Hot” } else if (temperature > 23) { show “Warm” } else { show “Cool” }
    The temperature is 11 °C. What is shown? (a) Warm (b) Cool (c) Hot
26. 26.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) in series (b) not joined (c) in parallel (d) by Wi-Fi
27. 27.Which of these is an insulator? (a) a graphite rod (b) a rubber eraser (c) a metal paper clip (d) aluminium foil
28. 28.🔺 A current of 1.5 A flows when 12 V is joined across a resistor. What is its resistance (in ohms)?
29. 29.🔺 A 0.8 V supply is joined across an 8 Ω resistor. What current flows (in amperes)? =
30. 30.🤖 if (light < 200 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 580 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
31. 31.⏱️ loop forever { LED ON; wait 900 ms; LED OFF; wait 650 ms }
    How many milliseconds does one blink (ON + OFF) take?
32. 32.📏 How many ohms (Ω) is 0.9 kΩ?
33. 33.🧩 Which component smooths a wobbly supply? (a) transistor (b) diode (c) thermistor (d) capacitor
34. 34.True or false: to throw cells in a fire is safe. (a) False (b) True
35. 35.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
36. 36.True or false: to dry your hands first is safe. (a) False (b) True
37. 37.🤖 Microcontroller or laptop: which one uses very little power? (a) laptop (b) microcontroller
38. 38.True or false: to take cells out after use is safe. (a) True (b) False
39. 39.🔋 What should you do with used-up cells? (a) bury them in soil (b) cut them open (c) throw them in a fire (d) give them for recycling
40. 40.True or false: to open blinds at sunrise, use a temperature sensor. (a) False (b) True

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