<p>Computational research was conducted in a miniature channel to study how a magnetic strength and sine waves interact with one another to influence heat transmission and pressure decrease for cooling a heat sink. The working fluid, a magnetic nanofluid made of Fe₃O₄, is utilised. The Reynolds number, Re, used from 150 to 210, while the intensity of the magnetic field is from 1200 to 2000 G. The numerical simulations were carried out with the assistance of the finite-volume computational fluid dynamics, ANSYS-Fluent 18.1. As the magnetic fields of 1200 G, 1500 G, and 2000 G are applied at <i>x</i>/<i>D</i> = 2.58 and 7.91, the findings reveal that there is a rise in the Nusselt numbers as compared to the flow without a magnetic field (<i>G</i> = 0) and the changes are significant because of the greater turbulence; it is abundantly obvious that the two sources located have a bigger increment in the Nusselt values in comparison with a single source. When a magnetic field of 1200 G, 1500 G, or 2000 G is applied at <i>x</i>/<i>D</i> = 2.58 and 7.91, there is a decrease trend in the friction factor with increasing Reynolds number. The increase in pressure drop occurs when compared to flow without a magnetic field. This occurs because the magnetic fields cause a gradient in the magnetic flux. This pattern holds true only when the intensity of the magnetic field is very strong.</p>