The relations between shear stress ( $\tau$ ) and velocity gradient for ideal fluids, Newtonian
fluids and non – Newtonian fluids are given below. Select the correct combination
(a) $\tau = 0, \tau = \mu (du/dy)^{2} ; \tau = u .(du/dy)^{3}$
(b) $\tau = 0, \tau = \mu (du/dy) ; \tau = u .(du/dy)^{2}$
(c) $\tau = 0, (du/dy) ; \tau = u .(du/dy)^{2} ; \tau = \mu .(du/dy)^{3}$
(d) $\tau = \mu (du/dy) ; \tau = u.(du/dy)^{2} ; \tau = 0$