A length-scale $(l)$ depends on the permittivity $(\varepsilon)$ of a dielectric material. Boltzmann constant $\left(k_B\right)$, the absolute temperature $(T)$, the number per unit volune $(n)$ of certain charged particles, and the charge $(q)$ carried by each of the particless. Which of the following expression($s$) for $l$ is(are) dimensionally correct?

($A$) $l=\sqrt{\left(\frac{n q^2}{\varepsilon k_B T}\right)}$

($B$) $l=\sqrt{\left(\frac{\varepsilon k_B T}{n q^2}\right)}$

($C$)$l=\sqrt{\left(\frac{q^2}{\varepsilon n^{2 / 3} k_B T}\right)}$

($D$) $l=\sqrt{\left(\frac{q^2}{\varepsilon n^{1 / 3} k_B T}\right)}$

  • [IIT 2016]
  • A

    $B,A$

  • B

    $B,C$

  • C

    $C,A$

  • D

    $B,D$

Similar Questions

Match List $I$ with List $II$

List $I$ List $II$
$A$ Spring constant $I$ $(T ^{-1})$
$B$ Angular speed $II$ $(MT ^{-2})$
$C$ Angular momentum $III$ $(ML ^2)$
$D$ Moment of Inertia $IV$ $(ML ^2 T ^{-1})$

Choose the correct answer from the options given below

  • [JEE MAIN 2023]

If momentum $[ P ]$, area $[ A ]$ and time $[ T ]$ are taken as fundamental quantities, then the dimensional formula for coefficient of viscosity is :

  • [JEE MAIN 2022]

The dimensions of shear modulus are

Out of following four dimensional quantities, which one quantity is to be called a dimensional constant

Given below are two statements: One is labelled as Assertion $(A)$ and other is labelled as Reason $(R)$.

Assertion $(A)$ : Time period of oscillation of a liquid drop depends on surface tension $(S)$, if density of the liquid is $p$ and radius of the drop is $r$, then $T = k \sqrt{ pr ^{3} / s ^{3 / 2}}$ is dimensionally correct, where $K$ is dimensionless.

Reason $(R)$: Using dimensional analysis we get $R.H.S.$ having different dimension than that of time period.

In the light of above statements, choose the correct answer from the options given below.

  • [JEE MAIN 2022]