Why do two layers of cloth of equal thickness provide warmer covering than a single layer of cloth of double the thickness?

What is the double layered covering of the lungs called ?

Why are woollen clothes warmer then cotton ?

The given figure shows the thickness of the uterine layer of an adult woman during a period of time Which of the following conditions is expected to occur in the beginning, if the curve continues along the dotted line ?

Ratio of coefficient of thermal conductivity of two different material is 4 : 3. to have same thermal resistance of the two rods of these materials of equal thickness, what should be the ratio of their length ?

A plate of metal 0.1 m^2 in area rests on a layer of caster oil 0.2 cm thick whose co efficient of viscosity is 15.5 poise. Calculate the horizontal force required to move the plate with a speed of 0.3 m/s.

An insulating wall consists of 4cm of material of thermal conductivity K_1 and a second layer of 8 cm thickness whose conductivity K_2 = 4K_1 . The innermost and outermost surfaces are kept at -10^@ C and 76^@ C respectively. Calculate the temperature at the interface.

On a winter night you feel warmer when clouds cover the sky than when the sky is clear why ?

Assertion:The outermost covering of a dicotyledonous seed in the seed coat. Reason:The seed coat has two layers-outer testa and inner helium.