Two solid spheres of radii 5cm and 3cm are made of same material and have similar surface. The spheres are raised to the same temperature and then allowed to cool under identical conditions. The ratio of rate of fall of temperature is

Two solid spheres of radii R_(1) and R_(2) are made of the same material and have similar surfaces. These are raised to the same temperature and then allowed to cool under identical conditions. The ratio of their initial rates of loss of heat are

Two solid spheres of radii R_(1) and R_(2) are made of same material and have similar surface. The spheres are raised to the same temperature and then allowed to cool under identical conditions. Assuming spheres to be perfect conductors of heat, their initial ratio of rates of loss of heat is:

A solid cube and a sphere are made of the same material and both have the same surface area. If both are at the temperature of 300 K then initial

Two metallic spheres A and B are made up of same material and also have identical surfaces. Both spheres are heated to same temperature and are then placed in a chamber which is at a lower temperature, thermally insulated from each other. If ratio of masses of A and B is 3:1, then the ratio of their initial rate of cooling is

A solid copper cube and sphere, both of same mass & emissivity are heated to same initial temperature and kept under identical conditions. What is the ratio of their initial rate of fall of temperature ?

A solid sphere, a cube and a plate, all are made of same material and all have same mass. These are heated to a temperature 100^@C and then allowed to cool at the temperature of room. Which of these will cool down first –

Two spheres of radii R_(1) and R_(2) are made of the same material and are at the same temperature. The ratio of their thermal capacities is: