A, B, C and D are four different physical quantities having different dimensions. None of the them is dimensionless. But we know that the equation AD = C In (BD) holds true. Then which of the combination is not a meaningful quantity?(i) CBD−AD2C(ii) A2−B2C2(iii) AB−C(iv) A−CD

Given, A, B, C and D have different dimensions. Also, AD = C in (BD)log is the dimensionless, so [B] =1DAlso, [AD] = [C](i) CBD=C1=CAD2C=ADDC=DSo, CBD−AD2C=C−D which is not meaningful.(ii) B2C2=B2A2D2=A2BD2=A2∴A2−B2C2 is meaningful(iii) AB=AD=C∴AB−C is meaningful(iv) A−CD is not meaningful as A and C both have difference dimensions.