Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 748 · 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.🤖 “if (A AND B)” is true when … (a) both A and B are true (b) only A is true (c) both are false (d) only B is true
2. 2.True or false: to close the fridge quickly wastes electricity. (a) True (b) False
3. 3.True or false: on a cell, “usually the red wire” means the − (negative) end. (a) True (b) False
4. 4.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they all go out (b) they keep glowing (c) they explode (d) they get dimmer
5. 5.🔌 Is a rubber band a conductor or an insulator? (a) an insulator (b) a conductor
6. 6.🔺 A current of 3 A flows through a 3 Ω resistor. What is the voltage across it (in volts)? =
7. 7.🔺 A current of 0.5 A flows through a 5 Ω resistor. What is the voltage across it (in volts)? =
8. 8.✏️ In a circuit diagram, which part is drawn as many long-short pairs? (a) battery (b) voltmeter (c) junction (d) switch
9. 9.🧾 A family uses 80 units of electricity in a month and each unit costs ₹5. What is the bill (in ₹)?
10. 10.🧩 Which component is a resistance knob? (a) diode (b) buzzer (c) potentiometer (d) capacitor
11. 11.Which of these is true of a series circuit? (a) own switch for each bulb (b) one out, the rest glow (c) used in house wiring (d) a single current path
12. 12.⚡ Which formula gives electric power? (a) P = V + I (b) P = V ÷ I (c) P = I ÷ V (d) P = V × I
13. 13.🌐 A weather station sends one reading every 30 seconds. How many readings does it send in 5 minutes?
14. 14.Which job needs a sound sensor? (a) start a fan when hot (b) measure classroom noise (c) close a window in rain (d) open blinds at sunrise
15. 15.🔦 A circuit has a used-up (dead) cell, a good bulb and a switch that is ON. All the wires are firmly joined. A gap in one wire is bridged by a cotton thread. Does the bulb glow? (a) Yes (b) No
16. 16.🔘 Which kind of switch springs back when let go? (a) a tilt switch (b) a toggle switch (c) a reed switch (d) a push button
17. 17.🧮 Resistors of 50 Ω, 33 Ω and 20 Ω are joined in series. What is the total resistance (in ohms)?
18. 18.💡 A blue LED uses 3 V and should get 10 mA. It runs from a 6 V supply. What resistor (in ohms) is needed in series?
19. 19.✏️ In a cell symbol, which line is the + terminal? (a) both lines (b) the shorter line (c) the longer line (d) neither line
20. 20.⚠️ Is it safe to dry your hands first? (a) not safe (b) safe
21. 21.True or false: if the loop is complete, the circuit is closed and current flows. (a) True (b) False
22. 22.🔺 A current of 1.5 A flows through a 12 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🌐 Is a smart energy meter an IoT device? (a) not an IoT device (b) an IoT device
24. 24.🔁 repeat 2 times { repeat 3 times { beep } }
    How many beeps are there?
25. 25.Which of these is measured in ohms (Ω)? (a) power (b) the push of a cell (c) energy used each second (d) resistance
26. 26.💡 Old festival light strings went fully dark when one bulb failed. How were they joined? (a) by Wi-Fi (b) not joined (c) in series (d) in parallel
27. 27.⏱️ How many milliseconds are in 1 second? (a) 100 (b) 10 (c) 1000 (d) 60
28. 28.⚡ A 1.5 W device works on 3 V. What current does it take (in amperes)? =
29. 29.🔁 count = 9
    repeat 2 times { count = count + 5 }
    What is count at the end?
30. 30.True or false: triangle, bar and arrows is the symbol for an LED. (a) True (b) False
31. 31.📶 Digital or analog: a knob turned part way? (a) analog (b) digital
32. 32.💡 5 identical bulbs are joined in series with a 10 V battery (ideal wires). How many volts does each bulb get? =
33. 33.⏱️ repeat 8 times { buzzer ON; wait 900 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
34. 34.💡 An LED (with its resistor) is on pin 8. All pins start LOW. The program runs once:
    set pin 8 LOW
    set pin 7 LOW
    set pin 7 HIGH
    set pin 7 HIGH
    set pin 8 HIGH
    Is the LED ON or OFF at the end? (a) ON (b) OFF
35. 35.🔺 A current of 20 mA flows when 3 V is joined across a resistor. What is its resistance (in ohms)?
36. 36.🧮 Resistors of 47 Ω and 330 Ω are joined in series. What is the total resistance (in ohms)?
37. 37.🔺 In the V-I-R triangle, how do we find V? (a) V = I × R (b) V = R ÷ I (c) V = I ÷ R (d) V = I + R
38. 38.🔁 count = 0
    repeat 2 times { count = count + 6 }
    What is count at the end?
39. 39.⚡ Power tells us … (a) the size of a cell (b) the length of a wire (c) the colour of light (d) energy used each second
40. 40.🔋 Does a refrigerator give electricity or use electricity? (a) gives electricity (b) uses electricity

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