Heat radiations propagate with the speed of

$A$ sphere,a cube,and a thin circular plate,all made of the same material and having the same mass,are heated to the same temperature of $200^{\circ} C$. When these are left in a room,which one reaches room temperature the fastest?

Which of the following is the correct device for the detection of thermal radiation?

The rate of emission of a body doubles when its temperature is increased by $10^{\circ}C$. If the temperature of the body is increased from $10^{\circ}C$ to $100^{\circ}C$,the rate of emission increases by a factor of:

The temperature of a blackbody radiation enclosed in a container of volume $V$ is increased from $100^{\circ} C$ to $1000^{\circ} C$. The heat required in the process is

Compared to a white-skinned person,what does a dark-skinned person experience?