Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 569 · 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.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. Does the bulb glow? (a) No (b) Yes
2. 2.💡 An LED is joined to a 12 V battery with no resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) lights up (b) may burn out (c) does not light
3. 3.What does a push button do? (a) closes near a magnet (b) stays where you flip it (c) flips up or down (d) works only while pressed
4. 4.🔁 Is the circuit closed or open if a wire is cut? (a) open (b) closed
5. 5.What does a slide switch do? (a) works only while pressed (b) closes when tipped over (c) slides side to side (d) closes near a magnet
6. 6.🤖 When the main loop of a microcontroller program ends, what happens? (a) it stops forever (b) the board breaks (c) it deletes itself (d) it starts again
7. 7.🧩 Which part changes electrical energy into sound? (a) a capacitor (b) a buzzer (c) a diode (d) a resistor
8. 8.True or false: triangle against a bar is the symbol for a voltmeter. (a) False (b) True
9. 9.💡 Does it save or waste electricity to set the AC to 24 °C? (a) saves electricity (b) wastes electricity
10. 10.🔌 Is a graphite rod a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.🔺 In the V-I-R triangle, how do we find R? (a) R = V ÷ I (b) R = I ÷ V (c) R = V × I (d) R = V + I
12. 12.📏 How many ohms (Ω) is 1.5 kΩ?
13. 13.🔍 Which is the odd one out? (a) a speaker (b) a push button (c) a buzzer (d) a small display
14. 14.⏱️ 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
15. 15.🧭 Which part of a microcontroller board keeps the voltage steady? (a) the pins (b) the reset button (c) the main chip (d) the voltage regulator
16. 16.🔁 What does a variable do in a program? (a) stores a value (b) blinks an LED (c) measures light (d) joins two wires
17. 17.Which of these is not safe? (a) keep drinks far away (b) dry your hands first (c) fly a kite near wires (d) use small battery cells
18. 18.🌐 How does a home IoT device usually send its data to the app? (a) by shouting (b) over Wi-Fi (c) through a candle (d) by post
19. 19.💡 Does it save or waste electricity to use old filament bulbs? (a) saves electricity (b) wastes electricity
20. 20.🔋 Identical cells side by side (in parallel) give … (a) the same voltage (b) half the voltage (c) no voltage (d) double the voltage
21. 21.🤖 Microcontroller or laptop: which one has no screen of its own? (a) laptop (b) microcontroller
22. 22.Which of these mainly makes movement? (a) an LED lamp (b) a torch (c) a tube light (d) an electric drill
23. 23.🔍 Which is the odd one out? (a) a night lamp (b) a tube light (c) a torch (d) an electric iron
24. 24.What does the microcontroller do? (a) shows data to you (b) carries the data (c) stores data online (d) reads values, decides
25. 25.✏️ Why do engineers draw circuits with symbols? (a) symbols are heavier (b) to make it colourful (c) quick and clear for all (d) to hide the circuit
26. 26.True or false: to start a fan when hot, use a temperature sensor. (a) True (b) False
27. 27.💡 Does it save or waste electricity to run fans in empty rooms? (a) wastes electricity (b) saves electricity
28. 28.True or false: on an LED, the leg by the flat edge is the anode (+). (a) False (b) True
29. 29.🤖 if (light < 400 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 430 and motion is not detected (false). What happens? (a) porch lamp ON (b) porch lamp OFF
30. 30.🔗 Series or parallel circuit: “a single current path”? (a) parallel (b) series
31. 31.🧮 Four equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.True or false: to set up with a parent is a risky habit. (a) True (b) False
33. 33.✏️ In a cell symbol, which line is the + terminal? (a) the longer line (b) both lines (c) the shorter line (d) neither line
34. 34.True or false: a plain wall switch usually has a microcontroller inside. (a) False (b) True
35. 35.🔺 An 18.8 V supply is joined across a 470 Ω resistor. What current flows (in milliamperes, mA)?
36. 36.⏱️ loop forever { LED ON; wait 350 ms; LED OFF; wait 800 ms }
    How many milliseconds does one blink (ON + OFF) take?
37. 37.🌈 A resistor has the colour bands grey, green, orange. What is its value (in ohms)?
38. 38.🔍 Which is the odd one out? (a) take cells out after use (b) use small battery cells (c) open a phone charger (d) build with an adult near
39. 39.Which job needs a motor? (a) show the temperature (b) open a gate to 90° (c) spin a robot’s wheels (d) beep an alarm
40. 40.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) it does not matter (d) only one

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