The average thermal conductivities of water and air conform to the ratio

Related MCQs

• A composite wall of a furnace has two layers of equal thickness having thermal conductivities in the ratio 2:3. What is the ratio of the temperature drop across the two layers?
• A composite wall is made of two layers of thickness δ1 and δ2 having thermal conductivities k and 2k and equal surface area normal to the direction of heat flow. The outer surface of composite wall are at 100 degree Celsius and 200 degree Celsius. The minimum surface temperature at the junction is 150 degree Celsius. What will be the ratio of wall thickness?
• Three metal walls of the same thickness and cross sectional area have thermal conductivities k, 2k and 3k respectively. The temperature drop across the walls (for same heat transfer) will be in the ratio
• Presence of moisture in the thermal insulating material increases thermal insulation while the presence of air spaces decreases thermal insulation.
• Which of the following is the correct relationship between thermal resistance and thermal conductivity?
• Which of the following is the correct relation between thermal transmittance and thermal time constant?
• Which one of the following forms of water have the highest value of thermal conductivity?
• 2 THERMAL EXPANSION OF SOLIDS AND LIQUIDS
• Thermal insulation keeps the room cool in winters and hot in summers.
• Reflective sheet materials used as thermal insulating material have                         reflectivity and                      emissivity.