Which two of the following five physical paramenters have the same dimensions?
(i) Energy density
(ii) Refractive index
(iii) Dielectric constant
(iv) Young's modulus
(v) Magnetic field

Options

A. 1 and 4
B. 1 and 5
C. 2 and 4
D. 3 and 5

Answer

A

Explanation

[Energy density]`=[("Work done")/("Volume")]=(MLT^(-2).L)/(L^(3))=[ML^(-1)T^(-2)]`
[Young.s modulus ]`=[Y][("Force")/("Area")]xx([L])/(Deltal)=(MLT^(-2))/(L^(2)) . L/L=[ML^(-1)T^(-2)]`
The dimensions of I and 4 are the same.