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Units & Dimensions

JEE Main level, single correct, medium

109 of 149

Question 109 of 149

If $e$ is the electronic charge, $c$ is the speed of light in free space and $h$ is Planck's constant, the quantity $\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{{\left|e\right|}^{2}}{hc}$ has dimensions of :

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Answer: (B) $\left[{M}^{0}{L}^{0}{T}^{0}\right]$

F=\dfrac{1}{4\pi {ϵ}_{0}}\dfrac{{e}^{2}}{{r}^{2}}

E=\dfrac{hc}{\lambda }

\left[\dfrac{{e}^{2}}{4\pi {\epsilon }_{0}}\times \dfrac{1}{hc}\right]=\dfrac{F{r}^{2}}{E\lambda }=\left({M}^{0}{L}^{0}{T}^{0}\right)

JEE Main question paper PDF

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JEE Main 2025 Apr 2 Shift 1 question paper

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More Physics practice

JEE Main Physics practice question on Units & Dimensions (Dimensions), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.

If eee is the electronic charge, ccc is the speed of light in free space and hhh is Planck's constant, the quantity 14πϵ0∣e∣2hc\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{{\left|e\right|}^{2}}{hc}4πϵ0​1​hc∣e∣2​ has dimensions of :

JEE Main question paper PDF

More Physics practice

If $e$ is the electronic charge, $c$ is the speed of light in free space and $h$ is Planck's constant, the quantity $\dfrac{1}{4\pi {\epsilon }_{0}}\dfrac{{\left|e\right|}^{2}}{hc}$ has dimensions of :