MEDIUM
11th West Bengal Board
IMPORTANT
Earn 100

What is the difference between thermal conductivity and thermal diffusivity.

Important Questions on Heat Transfer

MEDIUM
11th West Bengal Board
IMPORTANT
Find the dimensions of thermal conductivity.
EASY
11th West Bengal Board
IMPORTANT
Thermal conductivity of glass is 0.67 S.I.- explain the statement fully.
MEDIUM
11th West Bengal Board
IMPORTANT
Two metal bars A and B of the same size but of different materials are coated with equal thickness of wax and placed each with one end in a hot bath. It is noted that at first the wax on A melts at a greater rate than that on B but that when a steady state has been reached, a greater length of wax has melted on B than on A. Explain.
EASY
11th West Bengal Board
IMPORTANT
When a piece of metal cooled by liquid nitrogen (temperature =-180°C) is touched, a sensation of scorching is produced. Why?
EASY
11th West Bengal Board
IMPORTANT
In a place near the sea, a breeze blows from the sea to the land in the day time but it blows in the opposite direction at night. Why?
EASY
11th West Bengal Board
IMPORTANT
Two identical metallic cans contain some hot water. The walls of one can are polished while those of the other are blackened. In which can, the water will cool rapidly? Give reasons for your answer.
EASY
11th West Bengal Board
IMPORTANT
What do you mean by diathermanous and athermanous bodies?
EASY
11th West Bengal Board
IMPORTANT
Explain why felt rather than air is used for thermal insulation even though the thermal conductivity of air is less than that of felt?