Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 345 · 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.⏱️ How many milliseconds is a wait of 1.5 seconds?
2. 2.🔍 Which is the odd one out? (a) close the fridge quickly (b) switch off empty rooms (c) use daylight to read (d) leave the TV on standby
3. 3.True or false: on an LED, the shorter leg is the anode (+). (a) False (b) True
4. 4.What does a diode do? (a) is a resistance knob (b) lets current go one way (c) beeps for an alarm (d) senses how hot it is
5. 5.What does a transistor do? (a) stores a little charge (b) makes a beeping sound (c) boosts a small signal (d) senses how hot it is
6. 6.🧩 Which part changes electrical energy into sound? (a) a diode (b) a capacitor (c) a buzzer (d) a resistor
7. 7.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) False (b) True
8. 8.⚡ Power tells us … (a) the length of a wire (b) the size of a cell (c) the colour of light (d) energy used each second
9. 9.True or false: a paper strip is a conductor. (a) True (b) False
10. 10.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
11. 11.True or false: if a wire has come loose, the circuit is open and no current flows. (a) True (b) False
12. 12.🔁 x = 5
    repeat 5 times { x = x × 2 }
    What is x at the end?
13. 13.True or false: “how bright a room is” is a digital signal. (a) True (b) False
14. 14.⏱️ A program says “wait 3000 ms”. How many seconds is that? =
15. 15.🔁 Is the circuit closed or open if the loop is complete? (a) closed (b) open
16. 16.🌈 A resistor has the colour bands grey, red, orange. What is its value (in ohms)?
17. 17.🧩 Which component limits the current? (a) resistor (b) transistor (c) capacitor (d) motor
18. 18.🔍 Which is the odd one out? (a) open a phone charger (b) keep drinks far away (c) fly kites in open fields (d) dry your hands first
19. 19.🔍 Which is the odd one out? (a) a dry cork (b) a metal paper clip (c) a paper strip (d) a glass marble
20. 20.True or false: to build with an adult near is not safe. (a) False (b) True
21. 21.⏱️ How many milliseconds are in 1 second? (a) 1000 (b) 60 (c) 100 (d) 10
22. 22.True or false: to ignore update messages is a good habit. (a) True (b) False
23. 23.📶 On a 5 V board, a pin set HIGH gives about … (a) 50 V (b) 0 V (c) 5 V (d) 230 V
24. 24.🧩 Which component lets current go one way? (a) diode (b) capacitor (c) fuse (d) buzzer
25. 25.🔍 Which is the odd one out? (a) throw cells in a fire (b) dry your hands first (c) open a phone charger (d) poke things in a socket
26. 26.⚡ A bicycle dynamo changes which kind of energy into electricity? (a) movement energy (b) sound energy (c) light energy (d) chemical energy
27. 27.⚠️ Is it safe to take cells out after use? (a) safe (b) not safe
28. 28.True or false: “own switch for each bulb” is true of a parallel circuit. (a) False (b) True
29. 29.True or false: to switch on lamps at dusk, use a distance sensor. (a) True (b) False
30. 30.⏱️ A program says “wait 6500 ms”. How many seconds is that? =
31. 31.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 4 V supply. What current flows (in mA)?
32. 32.True or false: two equal parallel lines is the symbol for a switch. (a) True (b) False
33. 33.🔐 Is it a good or a risky habit to install software updates? (a) good habit (b) risky habit
34. 34.🔺 In the V-I-R triangle, how do we find V? (a) V = R ÷ I (b) V = I ÷ R (c) V = I × R (d) V = I + R
35. 35.🔺 A current of 2.5 A flows when 25 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.🔺 A current of 10 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
37. 37.True or false: “each gets the full volts” is true of a series circuit. (a) True (b) False
38. 38.💡 An LED is joined to a 5 V battery through a 220 Ω resistor; the leg next to the flat edge of its rim goes to the − side. What happens? (a) does not light (b) may burn out (c) lights up
39. 39.🤖 if (light < 300 AND motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 270 and motion is detected (true). What happens? (a) porch lamp OFF (b) porch lamp ON
40. 40.🔁 x = 4
    repeat 1 time { x = x × 2 }
    What is x at the end?

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