critical radius

A plastic sleeve of outer radius $${r_0} = 1\,\,mm$$ covers a wire (radius $$r = 0.5$$ $$mm$$) carrying electric current. Thermal conductivity of the plastic is $$0.15\,\,W/m$$-$$K...

A $$10$$ $$mm$$ diameter electrical conductor is covered by an insulation of $$2$$ $$mm$$ thickness. The conductivity of the insulation is $$0.08$$ $$W/m$$-$$K$$ and the convection...

A pipe of $$25$$ $$mm$$ outer diameter carries steam. The heat transfer coefficient between the cylinder and surrounding is $$5$$ $$W/{m^2}K.$$ It is propsed to reduce the heat los...

With an increase in the thickness of insulation around a circular pipe, heat loss to surroundings due to

A copper tube of $$20$$ $$mm$$ outer diameter, $$1$$ $$mm$$ thickness and $$20$$ $$m$$ long (Thermal conducti-vity$$ = 400$$ $$W/mK$$) is carrying saturated steam at $${150^ \circ...

It is proposed to coat a $$1mm$$ diameter wire with enamel paint $$\left( {k\,\,\,\, = 0.1W/m} \right.$$ - $$\left. K \right)$$ to increase heat transfer with air. If the air side...

For a current carrying wire of $$20$$ $$mm$$ diameter and having $$k=0.5W/mK$$ is exposed to air $$\left( {h = 20W/{m^2}K} \right),$$ maximum heat dissiption occurs when thickness...