Back to Directory
NEET PHYSICSMedium

If energy (EE), velocity (vv) and time (TT) are chosen as the fundamental quantities, the dimensional formula of surface tension will be:

A

[Ev2T1][E v^{-2} T^{-1}]

B

[Ev1T2][E v^{-1} T^{-2}]

C

[Ev2T2][E v^{-2} T^{-2}]

D

[E2v1T3][E^{-2} v^{-1} T^{-3}]

Step-by-Step Solution

  1. Identify the standard dimensions: Energy (EE) = [ML2T2][ML^2T^{-2}] Velocity (vv) = [LT1][LT^{-1}] Time (TT) = [T][T] Surface Tension (SS) = Force / Length = [MLT2]/[L]=[MT2][MLT^{-2}] / [L] = [MT^{-2}]

  2. Set up the dimensional equation: Let Surface Tension SEavbTcS \propto E^a v^b T^c S=kEavbTcS = k E^a v^b T^c (where kk is a dimensionless constant) Substituting the dimensions into the equation: [M1L0T2]=[ML2T2]a[LT1]b[T]c[M^1L^0T^{-2}] = [ML^2T^{-2}]^a [LT^{-1}]^b [T]^c [M1L0T2]=[MaL2a+bT2ab+c][M^1L^0T^{-2}] = [M^a L^{2a+b} T^{-2a-b+c}]

  3. Equate the powers of MM, LL, and TT: For MM: a=1a = 1 For LL: 2a+b=02a + b = 0 For TT: 2ab+c=2-2a - b + c = -2

  4. Solve for aa, bb, and cc: Since a=1a = 1, substituting in the LL equation: 2(1)+b=0b=22(1) + b = 0 \Rightarrow b = -2 Substituting aa and bb into the TT equation: 2(1)(2)+c=22+2+c=2c=2-2(1) - (-2) + c = -2 \Rightarrow -2 + 2 + c = -2 \Rightarrow c = -2

  5. Final Dimensional Formula: Substituting the values of aa, bb, and cc back into the assumed relation gives S=[E1v2T2]=[Ev2T2]S = [E^1 v^{-2} T^{-2}] = [E v^{-2} T^{-2}].

Practice Mode Available

Master this Topic on Sushrut

Join thousands of students and practice with AI-generated mock tests.

Get Started