A spinning wheel is brought in contact with an identical wheel spinning at identical speed. The wheels slow down under the action of friction. Which of the following energies of the first wheel decrease?

A spinning wheel A is brought in contact with another wheel B initially at rest. Because of the friction at contact, the second wheel also starts spinning. Which of the following energies of the wheel B increase?

A body A is placed on a railway platform and an identical body B in a moving train. Which of the following energies of B are greater than those of A as seen from the ground ?

The thermal conductivity of a rod depends on

1.  length

2.  mass

3.  area of cross section

4.  material of the rod.

One end of a metal rod is kept in a furnace. In steady state, the temperature of the rod

1.  increases

2.  decreases

3.  remains constant

4.  is nonuniform

One end of a metal rod is dipped in boiling water and the other is dipped in melting ice.

(a) All parts of the rod are in thermal equilibrium with each other.

(b) We can assign a temperature to the rod.

(c) We can assign a temperature to the rod after steady state is reached.

(d) The state of the rod does not change after steady state is reached

Choose the correct option 

1.  (a) , (b) 

2. (b) , (c) 

3.  (d) only 

4. (a) , (d)