Home
Class 12
PHYSICS
If the initial temperatures of metallic ...

If the initial temperatures of metallic sphere and disc, of the same mass, radius and nature are equal, then the ratio of their rate of cooling in same environment will be

A

`1:4`

B

`4:1`

C

`2:1`

D

`1:2`

Text Solution

Verified by Experts

The correct Answer is:
C
Given, radius of sphere=Radius of disc Rate of cooling `prop` Area of surface exposed
`("Rate of cooling of sphere")/("Rate of cooling of disc" )=(" Area of sphere")/("Area of disc")`
`=(4 piR^(2))/(2 piR^(2))=2/1`
Promotional Banner

Similar Questions

Explore conceptually related problems

Q.No 4-57, the ratio of their initial rates of cooling is:

A solid cylinder and a sphere of same material are suspended in a room turn by turn, after heating them to the same temperature. The cylinder and the sphere have same radius and same surface area. (a) Find the ratio of initial rate of cooling of the sphere to that of the cylinder. (b) Will the ratio change if both the sphere and the cylinder are painted with a thin layer of lamp black?

A solid sphere and a solid cylinder having the same mass and radius, rolls down the same incline. The ratio of their acceleration will be

Assertion : A solid sphere of copper of radius R and a hollow sphere of the same material of inner radius r and outer radius R are heated to the same temperature and allowed to cool in the same environment. The hollow sphere cools faster. Reason : Rate of cooling is according to Stefan's law which is E alpha T^(4)

A solid sphere of copper of radius R and a hollow sphere of the same materail of inner radius r and outer radius A are heated to the same temperature and allowed to cool in the same environment. Which of tehm starts cooling faster?

There are two thin spheres A and B of the same material and same thickness. They behave like black bodies, Radius of A is double that of B and Both have same temperature T. When A and B are kept in a room of temperature T_0 (lt T) , the ratio of their rates of cooling is (assume negligible heat exchange between A and B).

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

The edge of a cube is equal to the radius of a sphere. If the edge and the radius increase at the same rate, then the ratio of the increases in surface areas of the cube and sphere is