Test: Newton Rikhman Law - Mechanical Engineering MCQ

Forced air flows over a convection heat exchanger in a room heater, resulting in a convective heat transfer coefficient 1.136 k W/m² K. The surface temperature of heat exchanger may be considered constant at 65 degree Celsius, and the air is at 20 degree Celsius. Determine the heat exchanger surface area required for 8.8 k W of heating

A region of fluid motion near a plate in which temperature gradient exist is

Thermo-physical properties of the fluid are represented by
(i) Density
(ii) Viscosity
(iii) Specific heat
(iv) Thermal conductivity
Identify the correct option

A motor cycle cylinder consists of ten fins, each 150 mm outside diameter and 75 mm inside diameter. The average fin temperature is 500 degree Celsius and the surrounding air is at 20 degree Celsius temperature. Make calculations for the rate of heat dissipation from the cylinder fins by convection when motor cycle is stationary and convective coefficient is 6 W/m²K

Consider the above problem, make calculations for the rate of heat dissipation from the cylinder fins by convection when motor cycle is moving at 60 km/hr and convective coefficient is 75 W/m² K

The temperature profile at a particular location on a surface is prescribed by the identity
(t _s – t) / (t _s – t _infinity) = (1/2) (y/0.0075) ³ + (3/2) (y/0.0075)
If thermal conductivity of air is stated to be 0.03 W/m K, determine the value of convective heat transfer coefficient

Air at 20 degree Celsius flows over a flat surface maintained at 80 degree Celsius. The local heat flow at a point was measured as 1250 W/m² .Take thermal conductivity of air as 0.028 W/m K, calculate the temperature at a distance 0.5 mm from the surface