Question:
Which one of the following is a dimensionless constant?
Which one of the following is a dimensionless constant?
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The fine structure constant ($\alpha$) is dimensionless, and it's fundamental to quantum electrodynamics.
Updated On: Aug 30, 2025
- Permittivity of free space
- Permeability of free space
- Bohr magneton
- Fine structure constant
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The Correct Option is D
Solution and Explanation
- The fine structure constant, denoted by $\alpha$, is a dimensionless physical constant characterizing the strength of the electromagnetic interaction.
- The value of $\alpha$ is approximately 1/137 and is dimensionless.
- The other constants (permittivity of free space, permeability of free space, Bohr magneton) all have dimensions.
Thus, the correct answer is (D) Fine structure constant.
- The value of $\alpha$ is approximately 1/137 and is dimensionless.
- The other constants (permittivity of free space, permeability of free space, Bohr magneton) all have dimensions.
Thus, the correct answer is (D) Fine structure constant.
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