The momentum equations used by the authors are (Eqs. 1(*b*) and 1(*c*) in their paper)Display Formula

$u\u2202u\u2202x+v\u2202u\u2202y=\nu \u22022u\u2202y2+g\beta (T\u2212T\u221e)\u2212\sigma B02\rho (1+m2)(mu+w)$

(1)

Display Formula$u\u2202w\u2202x+v\u2202w\u2202y=\nu \u22022w\u2202y2\u2212\sigma B02\rho (1+m2)(mw\u2212u)$

(2)

where

$u$,

$v$, and

$w$ are the velocity components in

$x$,

$y$, and

$z$ directions,

$T$ is the fluid temperature,

$\beta $ is the volumetric expansion coefficient,

$\nu $ is the fluid kinematic viscosity,

$\rho $ is the fluid density,

$\sigma $ is the fluid electrical conductivity,

$B0$ is the magnetic induction and

$m$ is the Hall parameter. However, the last terms in the above two equations are wrong and the correct forms of Eqs.

1,

2 are as follows (Hossain and Arbad (

2), Pop and Watanabe (

3), Saha et al. (

4))

Display Formula$u\u2202u\u2202x+v\u2202u\u2202y=\nu \u22022u\u2202y2+g\beta (T\u2212T\u221e)\u2212\sigma B02\rho (1+m2)(u+mw)$

(3)

Display Formula$u\u2202w\u2202x+v\u2202w\u2202y=\nu \u22022w\u2202y2\u2212\sigma B02\rho (1+m2)(w\u2212mu)$

(4)

Taking into account that the Hall parameter

$m$ has been varied between 0.1 and 5 in the above work it is clear that the presented results and the conclusions are wrong.