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Experiment 02 · Circuit Diagram

Planck's Constant

+ − DC supply One-way key A B Rheostat Slider mA + − Milliammeter R = 1 kΩ + − LED V + − Voltmeter

Procedure

  1. 1.

    Make the connections according to the circuit diagram.

  2. 2.

    To connect a wire between two terminals, click on one terminal and drag the cursor to the other terminal.

  3. 3.

    Once all the connections are complete, select an appropriate LED.

  4. 4.

    Click the 'Insert Key' button.

  5. 5.

    Adjust the rheostat value gradually until the LED just begins to glow.

  6. 6.

    Record the voltage across the LED at this point as the knee voltage.

  7. 7.

    Repeat this process for the remaining LEDs.

  8. 8.

    Use the formula h = eλV / c to calculate the value of Planck's Constant.

Step 1 of 3

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