Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 35 · 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.✏️ In a circuit diagram, wires are usually drawn as … (a) wavy lines (b) little stars (c) straight lines (d) dotted circles
2. 2.True or false: voltage is measured in volts (V). (a) False (b) True
3. 3.⚡ A 9 W device works on 9 V. What current does it take (in amperes)? =
4. 4.🌈 A resistor has the colour bands yellow, green, yellow. What is its value in kilo-ohms (kΩ)? =
5. 5.⚠️ About how many volts do home sockets in India supply? (a) 230 V (b) 9 V (c) 1.5 V (d) 12 V
6. 6.🔍 Which is the odd one out? (a) a temperature reading (b) count button presses (c) a soil moisture reading (d) a button press
7. 7.🧮 Two equal 220 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
8. 8.⚡ A device works on 9 V and takes 1.5 A. What is its power (in watts)? =
9. 9.🧩 A capacitor in a circuit can … (a) spin a wheel (b) store charge briefly (c) make light (d) measure heat
10. 10.🔌 Is a metal paper clip a conductor or an insulator? (a) an insulator (b) a conductor
11. 11.⚡ A 72 W device works on 24 V. What current does it take (in amperes)? =
12. 12.🔁 Is the circuit closed or open if a wire has come loose? (a) open (b) closed
13. 13.🔐 Is it a good or a risky habit to change default passwords? (a) good habit (b) risky habit
14. 14.🔍 Which is the odd one out? (a) a Wi-Fi weather station (b) an app-controlled bulb (c) a Wi-Fi doorbell camera (d) a plain wall switch
15. 15.Which of these is an output? (a) a motion sensor (b) a keypad (c) a small display (d) a turning knob
16. 16.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = I + R (c) V = R ÷ I (d) V = I ÷ R
17. 17.🔺 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
18. 18.True or false: if all wires are joined, the circuit is open and no current flows. (a) False (b) True
19. 19.🔋 On a cell, does “the longer symbol line” mean the + end or the − end? (a) − (negative) (b) + (positive)
20. 20.🧾 Which lamp gives the same light for the least power? (a) an LED lamp (b) a filament bulb (c) a candle (d) an oil lamp
21. 21.True or false: to build with an adult near is not safe. (a) False (b) True
22. 22.True or false: a dry cork is an insulator. (a) True (b) False
23. 23.🔌 Is a wooden stick a conductor or an insulator? (a) a conductor (b) an insulator
24. 24.⏱️ How many milliseconds are in 1 second? (a) 10 (b) 100 (c) 60 (d) 1000
25. 25.🔘 A cell, a bulb and switches A and B are joined one after another in a single loop (series). A is OFF and B is OFF. Does the bulb glow? (a) Yes (b) No
26. 26.⚠️ Is it safe to build with an adult near? (a) not safe (b) safe
27. 27.🔋 How many volts does one ordinary torch cell give? (a) 230 V (b) 1.5 V (c) 15 V (d) 0.5 V
28. 28.What does a push button do? (a) flips up or down (b) slides side to side (c) springs back when let go (d) closes when tipped over
29. 29.Which of these is the input? (a) check if temp > 30 (b) an alert on the phone (c) the pump turns on (d) a soil moisture reading
30. 30.True or false: on a cell, “usually the red wire” means the + (positive) end. (a) True (b) False
31. 31.🧮 Two equal 1000 Ω resistors are joined in parallel. What is the total resistance (in ohms)?
32. 32.🔘 When a switch is ON, the circuit is … (a) broken (b) closed (c) open (d) cut
33. 33.Which of these gives us electricity? (a) a washing machine (b) a refrigerator (c) a television (d) a cell
34. 34.🔺 A current of 1.5 A flows through a 2 Ω resistor. What is the voltage across it (in volts)? =
35. 35.🔗 Series or parallel circuit: “a break stops every bulb”? (a) series (b) parallel
36. 36.🔁 total = 0
    for i = 1 to 10 { total = total + i }
    What is total at the end?
37. 37.🔋 2 identical 1.5 V cells are joined side by side in parallel (all + ends together, all − ends together). What is the voltage across them (in volts)? =
38. 38.🔁 count = 4
    while (count < 8) { count = count + 2 }
    How many times does the loop run?
39. 39.🔍 An object is 68 cm from a distance sensor. Sound travels about 34 cm every millisecond. After how many milliseconds does the echo come back?
40. 40.🔍 Which is the odd one out? (a) a loudspeaker (b) a siren (c) a buzzer (d) an electric kettle

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