Question

The unit of Planck's constant is:

• A. Joule/s
• B. Joule-s
• C. Joule-$m^{2}$
• D. Joule-m

Hint:

Planck's constant has the same dimensions as angular momentum ($[ML^{2}T^{-1}]$).

Answer 1

The Correct Option is B

Step 1: Concept
According to Planck's equation, $E = h\nu$, where $E$ is energy and $\nu$ is frequency.
Step 2: Analysis
$h = E/\nu$. The unit of energy is Joule ($J$) and the unit of frequency is $s^{-1}$.
Step 3: Conclusion
Thus, the unit of $h$ is $J / s^{-1} = J \cdot s$.
Final Answer: (B)