Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 208 · 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 new cell, a bulb with a broken filament and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a glass marble. Does the bulb glow? (a) Yes (b) No
2. 2.🤖 if (temperature > 32) { show “Hot” } else if (temperature > 26) { show “Warm” } else { show “Cool” }
   The temperature is 45 °C. What is shown? (a) Cool (b) Hot (c) Warm
3. 3.Which job needs a motor? (a) open a gate to 90° (b) spin a robot’s wheels (c) move water to plants (d) turn to an exact angle
4. 4.🧮 Two equal 40 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
5. 5.🔁 x = 2
   repeat 4 times { x = x × 2 }
   What is x at the end?
6. 6.🔋 How many volts does one ordinary torch cell give? (a) 0.5 V (b) 230 V (c) 1.5 V (d) 15 V
7. 7.🤖 Does a toy robot usually have a microcontroller inside? (a) No (b) Yes
8. 8.True or false: an LED glows using little power. (a) False (b) True
9. 9.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
10. 10.💡 On an LED, is the round-side leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
11. 11.Which of these is safe? (a) fly a kite near wires (b) touch a fallen wire (c) stop if a part gets hot (d) open a phone charger
12. 12.🗺️ In an input → process → output plan, is “a soil moisture reading” the input, the process or the output? (a) process (b) input (c) output
13. 13.🔺 A current of 40 mA flows through a 150 Ω resistor. What is the voltage across it (in volts)? =
14. 14.Which of these means the circuit is closed? (a) a wire has come loose (b) a cell is taken out (c) all wires are joined (d) the bulb is unscrewed
15. 15.🔐 Why install updates on IoT devices? (a) they make it heavier (b) they delete the Wi-Fi (c) they fix security holes (d) they change the colour
16. 16.🧮 Two equal 470 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
17. 17.🔘 A cell and a bulb are joined to 2 side-by-side paths with one switch on each path — A and B (parallel). A is OFF and B is ON. Does the bulb glow? (a) No (b) Yes
18. 18.🔺 In the V-I-R triangle, how do we find I? (a) I = V ÷ R (b) I = V × R (c) I = V + R (d) I = R ÷ V
19. 19.True or false: energy used each second is measured in watts (W). (a) False (b) True
20. 20.True or false: a resistor glows using little power. (a) False (b) True
21. 21.🌈 In the resistor colour code, which number does yellow stand for?
22. 22.True or false: to poke things in a socket is safe. (a) True (b) False
23. 23.⚡ What does a table fan mainly change electricity into? (a) heat (b) light (c) sound (d) movement
24. 24.Which of these is a good habit? (a) read app permissions (b) tap unknown app links (c) share the Wi-Fi key (d) keep factory passwords
25. 25.🧮 Five equal 250 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
26. 26.🌐 Is a paper calendar an IoT device? (a) an IoT device (b) not an IoT device
27. 27.🌈 Which band is read first on a resistor? (a) the gold band (b) the one nearest an end (c) the widest gap (d) any band
28. 28.⏱️ A program says “wait 9250 ms”. How many seconds is that? =
29. 29.🌈 A gold fourth band on a resistor means the value may be off by … (a) 5 % (b) 25 % (c) 0 % (d) 50 %
30. 30.🔺 A current of 40 mA flows when 6 V is joined across a resistor. What is its resistance (in ohms)?
31. 31.🔺 A current of 25 mA flows through a 250 Ω resistor. What is the voltage across it (in volts)? =
32. 32.📏 In the water-pipe picture of a circuit, current is like … (a) the pipe colour (b) the water pressure (c) a narrow pipe (d) the flow of water
33. 33.🔗 Series or parallel circuit: “one out, the rest glow”? (a) parallel (b) series
34. 34.📏 Which unit measures voltage? (a) watt (W) (b) ampere (A) (c) ohm (Ω) (d) volt (V)
35. 35.True or false: a toggle switch closes near a magnet. (a) True (b) False
36. 36.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) ON (b) OFF
37. 37.⚠️ About how many volts do home sockets in India supply? (a) 1.5 V (b) 9 V (c) 230 V (d) 12 V
38. 38.Which of these mainly makes movement? (a) a traffic signal (b) an electric iron (c) a loudspeaker (d) an electric drill
39. 39.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 7 LOW
    set pin 8 LOW
    set pin 7 HIGH
    set pin 7 LOW
    Is the LED ON or OFF at the end? (a) OFF (b) ON
40. 40.🤖 Where does the board keep its program when the power is off? (a) the power LED (b) the resistor (c) the USB cable (d) flash memory

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