If dimensions of critical velocity vc of a liquid flowing through a tube are expressed as\( [\eta^x \rho^y r^z] \)where \(\eta\), \(\rho\) and r are the coefficient of viscosity of liquid, density of liquid and radius of the tube respectively, then the values of x, y and z are given by :

1, 1, 1 1, -1, -1 -1, -1, 1 -1, -1, -1

1, -1, -1

Critical velocity : \( v_c = \frac{R\eta}{\rho D} \) ⇒ x = 1, y = – 1, z = – 1