Water flows at a rate of 0.25 kg/sec in a 2.5 cm diameter tube having a length of 3m. Constant heat flux is imposed at the tube wall so that the tube wall temperature is 40C higher than the water temperature. Calculate the heat transfer from the tube wall to the water. Thewater is pressurized so that boiling cannot occur. Assume a heat transfer coefficient of 3500W/m2C.

68.75W

Explanation:

Heat transfer is describe as the flow of thermal energy as a result of changes in temperature between two or more bodies. Heat  transferred via solid bodies is called conduction, and that associated with liquids and gases  is called convection, and likewise, the one attributed to electromagnetical waves  is called radiation.

heat transfer from the tube wall to the water = kA.ΔT

= 3500* π* (2.5 * 10⁻²)²/4 *40

= 68.75W

The value of the current in the wire is 300 A.

Explanation:

The current can be determined by;

       B =

Where: B is the magnetic field, I is the current, r id the distance between the wire and sensor and is a constant called the permeability of the free space.

From the given question, r = 2 m, B = 3 × T and   = 4 × × Tm

So that;

         I =

           = (2 × × 2 × 3 × ) ÷ (4 × × )

           = 300 A

The value of the current in the wire would be 300 A.