Virtual Labs

To simulate interfacing of basics output components (RGB Led, 7 segment, OLED, LCD 16*2 and buzzer) with Arduino.

1. Explain common cathode vs common anode 7-segment display.

a: Common cathode has all grounds connected; common anode has all positives connected. Explanation

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b: Common cathode uses analog signals; common anode uses digital signals. Explanation

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c: Common cathode has fewer pins. Explanation

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d: Common anode works only with AC supply. Explanation

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2. How can Arduino generate multiple colors on an RGB LED?

a: By mixing PWM signals on the red, green, and blue pins. Explanation

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b: By changing the input voltage. Explanation

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c: By connecting it to analog input pins. Explanation

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d: By rotating the LED physically. Explanation

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3. Why is OLED preferred in modern IoT dashboards?

a: It consumes low power and gives high contrast display. Explanation

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b: It requires no programming. Explanation

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c: It can only display text. Explanation

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d: It works only in dark conditions. Explanation

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4. Describe the internal working of an LCD 16×2.

a: It uses a controller (HD44780) to drive characters in a dot matrix. Explanation

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b: It displays text using OLED pixels. Explanation

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c: It stores each character in RAM permanently. Explanation

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d: It uses LEDs behind every character. Explanation

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5. How can you display sensor data on LCD?

a: Read sensor → convert to value → use lcd.print(). Explanation

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b: Write sensor data directly to the LCD pins. Explanation

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c: Use digitalWrite() for text display. Explanation

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d: Use the LCD to sense data. Explanation

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6. What is the difference between active and passive buzzer?

a: Active buzzer has built-in oscillator; passive needs tone() to generate sound. Explanation

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b: Passive buzzer is louder always. Explanation

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c: Active buzzer can read input signals. Explanation

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d: Both work only with analog input. Explanation

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7. How does I2C communication reduce pin usage?

a: It uses only two lines (SDA, SCL) for multiple devices. Explanation

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b: It disables unused pins. Explanation

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c: It converts analog pins into digital pins. Explanation

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d: It transmits data without wires. Explanation

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8. What happens when incorrect wiring is done for 7-segment display?

a: Some segments will glow incorrectly or not at all. Explanation

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b: It will automatically correct the connection. Explanation

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c: It will display all numbers perfectly. Explanation

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d: It will reset Arduino. Explanation

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9. Give a real-life application of buzzer in IoT.

a: Home security alarm system. Explanation

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b: Video streaming device. Explanation

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c: Weather forecast display. Explanation

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d: LED street light. Explanation

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10. How can brightness of RGB LED be controlled in simulation?

a: By using PWM output through analogWrite() on each color pin. Explanation

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b: By changing digitalRead() values. Explanation

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c: By using Serial Monitor. Explanation

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d: By rotating the LED wires. Explanation

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