Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 70 · 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.⚠️ About how many volts do home sockets in India supply? (a) 9 V (b) 1.5 V (c) 12 V (d) 230 V
2. 2.🔍 Which is the odd one out? (a) use small battery cells (b) open a phone charger (c) throw cells in a fire (d) use mains for a project
3. 3.⚠️ Is it safe to keep drinks far away? (a) safe (b) not safe
4. 4.🔺 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
5. 5.🔍 Which is the odd one out? (a) keep factory passwords (b) share camera links (c) post your live location (d) log out of shared phones
6. 6.💡 In a parallel circuit, one bulb breaks. What happens to the others? (a) they get dimmer (b) they explode (c) they keep glowing (d) they all go out
7. 7.🔍 Which is the odd one out? (a) a safety pin (b) a wooden stick (c) an iron nail (d) a brass key
8. 8.🔁 Is the circuit closed or open if the switch is OFF? (a) closed (b) open
9. 9.🔁 x = 5
   repeat 1 time { x = x × 2 }
   What is x at the end?
10. 10.🔍 Which is the odd one out? (a) dry your hands first (b) use small battery cells (c) build with an adult near (d) touch a switch when wet
11. 11.🔘 Which kind of switch works only while pressed? (a) a slide switch (b) a tilt switch (c) a reed switch (d) a push button
12. 12.🔁 count = 0
    while (count < 30) { count = count + 5 }
    How many times does the loop run?
13. 13.🔍 A distance sensor sends a sound pulse and hears the echo 6 ms later. Sound travels about 34 cm every millisecond. How far away is the object (in cm)?
14. 14.💡 On an LED, is the longer leg the anode (+) or the cathode (−)? (a) anode (+) (b) cathode (−)
15. 15.🔺 A current of 0.5 A flows when 5 V is joined across a resistor. What is its resistance (in ohms)?
16. 16.🔋 Does a computer give electricity or use electricity? (a) gives electricity (b) uses electricity
17. 17.🧾 A 2000 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
18. 18.🔁 What does “count = count + 1” do? (a) sets count to 1 (b) adds 1 to count (c) prints 1 (d) takes 1 away
19. 19.Which of these is true of a parallel circuit? (a) many paths for current (b) a break stops every bulb (c) bulbs share the voltage (d) a single current path
20. 20.True or false: triangle against a bar is the symbol for a diode. (a) True (b) False
21. 21.🌐 In an IoT system, which part acts on a command? (a) phone app (b) sensor (c) microcontroller (d) actuator
22. 22.🤖 Does a smart watch usually have a microcontroller inside? (a) No (b) Yes
23. 23.True or false: a diode smooths a wobbly supply. (a) False (b) True
24. 24.🔺 A current of 25 mA flows through a 470 Ω resistor. What is the voltage across it (in volts)? =
25. 25.Which of these mainly gives out heat? (a) a buzzer (b) a torch (c) an exhaust fan (d) a water heater
26. 26.🧮 A 3 V battery is joined to 8 Ω and 4 Ω resistors in series. What current flows (in amperes)? =
27. 27.🔁 repeat 2 times { repeat 2 times { beep } }
    How many beeps are there?
28. 28.🤖 if (temperature > 32) { fan ON } else { fan OFF }
    The temperature sensor reads 30 °C. What happens? (a) fan ON (b) fan OFF
29. 29.✏️ In a circuit diagram, which part is drawn as a dot where wires meet? (a) bulb (b) battery (c) junction (d) LED
30. 30.What does a capacitor do? (a) limits the current (b) blows if current is high (c) smooths a wobbly supply (d) has coloured bands
31. 31.⏱️ repeat 5 times { buzzer ON; wait 700 ms; buzzer OFF; wait 500 ms }
    How many milliseconds does this take in all?
32. 32.⚡ A solar panel changes which kind of energy into electricity? (a) light energy (b) chemical energy (c) sound energy (d) wind energy
33. 33.🔺 A current of 50 mA flows through a 330 Ω resistor. What is the voltage across it (in volts)? =
34. 34.🤖 if (temperature > 36) { show “Hot” } else if (temperature > 20) { show “Warm” } else { show “Cool” }
    The temperature is 42 °C. What is shown? (a) Hot (b) Warm (c) Cool
35. 35.🔘 What does a switch do in a circuit? (a) changes the voltage (b) opens or closes the loop (c) stores current (d) makes electricity
36. 36.True or false: “many paths for current” is true of a series circuit. (a) False (b) True
37. 37.Which of these is a conductor? (a) a brass key (b) a paper strip (c) a rubber band (d) a cotton thread
38. 38.True or false: a microcontroller needs much more power. (a) True (b) False
39. 39.💡 An LED (with its resistor) is on pin 7. All pins start LOW. The program runs once:
    set pin 8 HIGH
    set pin 7 HIGH
    Is the LED ON or OFF at the end? (a) OFF (b) ON
40. 40.True or false: triangle, bar and arrows is the symbol for a diode. (a) True (b) False

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