What is the value of Planck's constant (h) in erg-s and joule-s respectively?

The Planck's constant (h) is a fundamental universal constant that plays a pivotal role in quantum mechanics. It establishes the quantum nature of energy and forms the basis for the relationship between the energy of a photon and its frequency. The formula that incorporates Planck's constant is:

E = h × f

Value of Planck's Constant in SI and CGS Units

• In the SI system, the value of Planck's constant is given as: h = 6.626 × 10^-34 Js, where J represents joules and s represents seconds.
• In the CGS system, the value of Planck's constant is: h = 6.62619 × 10^-27 erg-s. The unit erg is a smaller unit of energy compared to joules, commonly used in the CGS system.

Importance of Planck's Constant

Planck's constant is critical for understanding quantum mechanics and is essential for calculations involving the energy of photons. For instance, it is used in determining the value of hc, which combines Planck's constant with the speed of light (c), often utilized in equations related to the wavelength of light and energy transitions in atoms.

Value of hc

The value of hc is a derived constant that simplifies many calculations in quantum physics. It is expressed as the product of Planck's constant (h) and the speed of light (c):

h_c = (6.626 × 10^-34 Js) × (3.00 × 10⁸ m/s) = 1.986 × 10^-25 J·m.

In the CGS system, the value of hc is:

h_c = (6.62619 × 10^-27 erg-s) × (3.00 × 10¹⁰ cm/s) = 1.986 × 10^-16 erg·cm.

Conclusion

Understanding the value of Planck's constant (h) in different units and its derived quantities, such as the value of hc, is crucial for exploring the quantum nature of energy, photons, and light-matter interactions. These constants bridge the gap between classical and quantum physics, making them indispensable in scientific studies.