Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 282 · 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: on an LED, the leg by the flat edge is the cathode (−). (a) False (b) True
2. 2.🌈 A gold fourth band on a resistor means the value may be off by … (a) 50 % (b) 25 % (c) 0 % (d) 5 %
3. 3.💡 In a series circuit, how many paths does the current have? (a) two (b) one (c) none (d) one for each bulb
4. 4.🔦 A tester circuit has a new cell, a good bulb and wires with a gap between two clips. We put a copper wire across the gap. Does the bulb glow? (a) Yes (b) No
5. 5.🤖 if (temperature > 37) { show “Hot” } else if (temperature > 22) { show “Warm” } else { show “Cool” }
   The temperature is 12 °C. What is shown? (a) Warm (b) Cool (c) Hot
6. 6.💡 A red LED (it uses 2 V) is joined with a 200 Ω resistor to a 6 V supply. What current flows (in mA)?
7. 7.🔌 Is aluminium foil a conductor or an insulator? (a) an insulator (b) a conductor
8. 8.🧩 Which part changes electrical energy into movement? (a) a motor (b) a resistor (c) a fuse (d) an LED
9. 9.Which of these is an insulator? (a) a metal paper clip (b) a brass key (c) aluminium foil (d) a glass marble
10. 10.Which of these gives us electricity? (a) a television (b) a refrigerator (c) a mobile phone (d) a cell
11. 11.🔗 Series or parallel circuit: “used in house wiring”? (a) series (b) parallel
12. 12.⚠️ Which power source should children use for electronics projects? (a) a mains extension board (b) a wall socket (c) an inverter socket (d) a small battery pack
13. 13.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 1000 (c) 60 (d) 100
14. 14.🌐 A weather station sends one reading every 20 seconds. How many readings does it send in 7 minutes?
15. 15.🌐 A soil sensor sends a reading to an app every 20 minutes. How many readings arrive in 5 hours?
16. 16.True or false: to keep an incubator warm, use a distance sensor. (a) True (b) False
17. 17.Which of these is the output? (a) a soil moisture reading (b) a button press (c) a light level reading (d) the fan starts
18. 18.🔌 Which metal is used for most electric wires at home? (a) plastic (b) rubber (c) glass (d) copper
19. 19.🤖 if (light < 300 OR motion) { porch lamp ON } else { porch lamp OFF }
    The light reading is 90 and motion is detected (true). What happens? (a) porch lamp ON (b) porch lamp OFF
20. 20.True or false: an LDR senses how bright it is. (a) True (b) False
21. 21.True or false: the ammeter measures voltage. (a) False (b) True
22. 22.🔢 To plan an electronics project, which comes first: “pick a problem to solve” or “draw the circuit diagram”? (a) draw the circuit diagram (b) pick a problem to solve
23. 23.🔢 To get a sensor reading onto a phone, what comes right after “the cloud stores it”? (a) the sensor measures (b) the app shows it (c) the board reads it (d) it is sent by Wi-Fi
24. 24.🌐 In an IoT system, which part acts on a command? (a) Wi-Fi (b) phone app (c) actuator (d) cloud server
25. 25.True or false: to post your live location is a good habit. (a) True (b) False
26. 26.📶 On a 5 V board, a pin set HIGH gives about … (a) 5 V (b) 230 V (c) 0 V (d) 50 V
27. 27.🔗 Series or parallel circuit: “many paths for current”? (a) series (b) parallel
28. 28.🔁 What does a variable do in a program? (a) joins two wires (b) stores a value (c) measures light (d) blinks an LED
29. 29.Which of these is measured in watts (W)? (a) how much a part resists (b) resistance (c) power (d) current
30. 30.🔺 In the V-I-R triangle, how do we find R? (a) R = V × I (b) R = V + I (c) R = V ÷ I (d) R = I ÷ V
31. 31.🌐 A soil sensor sends a reading to an app every 15 minutes. How many readings arrive in 2 hours?
32. 32.🔍 Which is the odd one out? (a) a paper strip (b) a wooden stick (c) a woollen thread (d) a safety pin
33. 33.Which of these is the input? (a) a temperature reading (b) the fan starts (c) an LED lights up (d) decide if soil is dry
34. 34.🔺 In the V-I-R triangle, how do we find I? (a) I = V × R (b) I = R ÷ V (c) I = V ÷ R (d) I = V + R
35. 35.Which of these gives us electricity? (a) a bicycle dynamo (b) an air conditioner (c) a television (d) a computer
36. 36.🔋 Identical cells side by side (in parallel) give … (a) double the voltage (b) no voltage (c) half the voltage (d) the same voltage
37. 37.🧮 Two equal 20 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
38. 38.🔁 In an old-style bulb, which thin wire glows when current flows? (a) the base (b) the filament (c) the switch (d) the glass
39. 39.💡 Does it save or waste electricity to leave fridge door open? (a) saves electricity (b) wastes electricity
40. 40.🌐 Is a plain wall switch an IoT device? (a) an IoT device (b) not an IoT device

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