According to nature of flow, convective heat transfer is classified into natural convection

and forced convection. By taking specific examples, explain how the natural convection

and forced convection arises in them

1.Radiator

2.Steaming cup of hot tea

3.Ice melting

Explanation:

1.Puts warm air out at the top and draws in cooler air at the bottom.

2.The steam is showing heat being transfered into the air.

3.Heat moves to the ice from the air. This causes the melting from a solid to liquid.

Explanation:

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.