Electronics Worksheet: Final Test

Electronics lesson 30: Final electronics test · Set 174 · 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.🔐 Is it a good or a risky habit to set a strong password? (a) good habit (b) risky habit
2. 2.⏱️ A program says “wait 750 ms”. How many seconds is that? =
3. 3.🌈 In the resistor colour code, which number does violet stand for?
4. 4.🔁 A bulb has two contacts. How many must be joined into the loop for it to glow? (a) both of them (b) none (c) it does not matter (d) only one
5. 5.📏 How many ohms make 1 kilo-ohm (kΩ)? (a) 1024 (b) 10 (c) 1000 (d) 100
6. 6.⚙️ Which actuator would you use to spin a robot’s wheels? (a) an LED (b) a buzzer (c) a motor (d) a display
7. 7.🔗 Series or parallel circuit: “own switch for each bulb”? (a) parallel (b) series
8. 8.🧾 A 200 W appliance runs for 2 hours. How many units (kWh) of electricity does it use? =
9. 9.⚡ A fan changes electrical energy mainly into which kind of energy? (a) movement energy (b) sound energy (c) chemical energy (d) light energy
10. 10.🌐 How does a home IoT device usually send its data to the app? (a) through a candle (b) by shouting (c) over Wi-Fi (d) by post
11. 11.🧩 Which component blows if current is high? (a) fuse (b) LED (c) motor (d) LDR
12. 12.🧩 Which part changes electrical energy into movement? (a) a fuse (b) a motor (c) a resistor (d) an LED
13. 13.💡 A red LED (it uses 2 V) is joined with a 100 Ω resistor to a 3 V supply. What current flows (in mA)?
14. 14.🧮 Resistors of 330 Ω and 10 Ω are joined in series. What is the total resistance (in ohms)?
15. 15.🌈 A resistor has the colour bands yellow, grey, orange. What is its value (in ohms)?
16. 16.🔁 x = 2
    repeat 2 times { x = x × 2 }
    What is x at the end?
17. 17.True or false: on an LED, the longer leg is the cathode (−). (a) True (b) False
18. 18.Which of these is an IoT device? (a) a Wi-Fi weather station (b) a plain wall switch (c) a wind-up clock (d) a pencil sharpener
19. 19.True or false: a graphite rod is a conductor. (a) False (b) True
20. 20.💡 2 identical bulbs are joined in series with a 4 V battery (ideal wires). How many volts does each bulb get? =
21. 21.🧩 Which component lets current go one way? (a) buzzer (b) diode (c) thermistor (d) LDR
22. 22.🔺 A current of 1 A flows through a 10 Ω resistor. What is the voltage across it (in volts)? =
23. 23.🔺 A current of 0.2 A flows when 1.2 V is joined across a resistor. What is its resistance (in ohms)?
24. 24.🔍 Which is the odd one out? (a) touch a switch when wet (b) open a phone charger (c) dry your hands first (d) poke things in a socket
25. 25.💡 6 identical bulbs are joined in parallel (each on its own side-by-side path) with a battery and a closed switch on the main wire. Bulb 1 is taken out of its holder. How many bulbs glow?
26. 26.🌈 A resistor has the colour bands yellow, black, red. What is its value in kilo-ohms (kΩ)? =
27. 27.🔘 What does a switch do in a circuit? (a) changes the voltage (b) stores current (c) opens or closes the loop (d) makes electricity
28. 28.⚡ A device works on 6 V and takes 0.1 A. What is its power (in watts)? =
29. 29.True or false: “how bright a room is” is an analog signal. (a) True (b) False
30. 30.📏 In the water-pipe picture of a circuit, voltage is like … (a) the water tank lid (b) the water pressure (c) the pipe colour (d) the tap handle
31. 31.🌐 In an IoT system, which part shows data to you? (a) Wi-Fi (b) sensor (c) phone app (d) microcontroller
32. 32.Which drawing is the symbol for a diode? (a) triangle against a bar (b) two or more cell symbols (c) a small empty box (d) a plain rectangle
33. 33.💡 An LED is joined to a 6 V battery through a 330 Ω resistor; its long leg goes to the + side and its short leg to the − side. What happens? (a) may burn out (b) lights up (c) does not light
34. 34.🧾 A 200 W appliance runs for 10 hours. How many units (kWh) of electricity does it use? =
35. 35.🌐 A soil sensor sends a reading to an app every 5 minutes. How many readings arrive in 3 hours?
36. 36.🧾 A family uses 190 units of electricity in a month and each unit costs ₹8. What is the bill (in ₹)?
37. 37.🌈 In the resistor colour code, which number does grey stand for?
38. 38.Which job needs a pump? (a) turn to an exact angle (b) move water to plants (c) beep an alarm (d) show a status light
39. 39.🔁 count = 0
    while (count < 20) { count = count + 4 }
    How many times does the loop run?
40. 40.True or false: “many paths for current” is true of a parallel circuit. (a) True (b) False

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