🛠️ JEE🧲 Physics

If \(\epsilon_{ o }\) is the permittivity of free space and \(E\) is the electric field, then \(\epsilon_{ o } E ^2\) ha…

Q1 FREE PREVIEW

If \(\epsilon_{ o }\) is the permittivity of free space and \(E\) is the electric field, then \(\epsilon_{ o } E ^2\) has the dimensions :

[JEE Main 2024, 8 Apr (Shift 2)]

a

\(\left[ M L ^{-1} T ^{-2}\right]\)

b

\(\left[ M L ^2 T ^{-2}\right]\)

c

\(\left[ M ^{\circ} L ^{-2} T A \right]\)

d

\(\left[ M ^{-1} L ^{-3} T ^4 A ^2\right]\)

✓ Correct answer: a)

\(\left[ M L ^{-1} T ^{-2}\right]\)

Explanation

\begin{equation}
\begin{aligned}
& \text { } E=\frac{Q}{4 \pi \varepsilon_0 R^2} \Rightarrow \varepsilon_0=\frac{Q}{4 \pi R^2 E} \\
& \text { Now, } \varepsilon_0 E^2=\frac{Q}{4 \pi R^2 E} \cdot E^2=\frac{Q}{4 \pi R^2} \cdot E \\
& {\left[\varepsilon_0 E^2\right]=\left[\frac{Q E}{R^2}\right]=\frac{[Q][E]}{\left[R^2\right]}=\frac{[Q]}{\left[R^2\right][Q][R]}[W]} \\
& =\frac{[W]}{\left[R^3\right]}=\frac{M L^2 T^{-2}}{L^3}=M L^{-1} T^{-2}
\end{aligned}
\end{equation}

Practice more JEE Physics PYQs

See every question on Units and Measurements, or browse the full JEE question bank.

See all questions on Units and Measurements →