Q: In which of the following process convection does not take place primarily?

\$\textbf{Explanation:}\$\$\bullet\$In convection, transfer of heat took place by movement of gaseous and liquid molecules.\$\bullet\$It generally happens in liquid and gas only where bulk portion is fluid. Sea and land breeze, trade wind and boiling water are example of such fluids. So, in those heat transfer is because of convection. But in bulb filament, resistance is responsible for transferring the heat which is example of conduction. So, in warming of glass bulb due to filament convection doesn’t take place. Hence, option D is the correct answer.

Question 1

In which of the following process convection does not take place primarily?

Accepted Answer

$\textbf{Explanation:}$$\bullet$In convection, transfer&#10;of heat took place by movement of gaseous and liquid molecules.$\bullet$It generally&#10;happens in liquid and gas only where bulk portion is fluid. Sea and land&#10;breeze, trade wind and boiling water are example of such fluids. So, in those&#10;heat transfer is because of convection. But in bulb filament, resistance is&#10;responsible for transferring the heat which is example of conduction. So, in&#10;warming of glass bulb due to filament convection doesn&#8217;t take place.&#10;&#10;Hence, option D is&#10;the correct answer.

Question 2

Heat always flows from higher temperature to lower temperature.

Accepted Answer

By the Second law of thermodynamics..the heat flows from an higher to lower region in terms of entropy.(Entropy is the measurement of order of disorderness of a system).The entropy of a hot body is more than that of a cold one.energy will always be transferred from the hotter to the cooler object. The objects will exchange thermal energy, until thermal equilibrium is reached,Hence statement is true

Question 3

Write two difference between conduction and convection

Accepted Answer

Conduction :1} It is the transfer of heat by direct contact.2) The reason for heat transfer is temperature difference.Convention:1) It involves the heat movement by actual motion of the matter.2) This process takes place due to difference in densities.

Question 4

The process of transfer of heat by the movement of particles of medium from one place to another is called

Accepted Answer

Process of heat transfer through movement of particles of medium from one place to another is convection.

Question 5

Which of the following is an example of convection?

Accepted Answer

Convection is a form of heat transfer where a large number of molecules move from one place to another. An overhead fan works precisely by this method: it sends cooler air molecules down into a hot room, cooling the temperature of the room. The heat of the sun and the cooking action of a microwave are both forms of radiation, while the heat on a frying pan and the cooling action of ice cubes are both forms of conduction.

Question 6

The direction of flow of heat between two bodies is determined by

Accepted Answer

The direction of flow of heat between two bodies is determined by their temperatures .Heat flows naturally from an object at a higher temperature to an object at a lower temperature .

Question 7

By opening the door of a refrigerator inside a closed room:

Accepted Answer

If the refrigerator door is open, heat is recycled from the room into the refrigerator, then back into the room. A net room temperature increase would result from the heat of the motor that would be constantly running (to which there is an external supply of electrical energy).

Question 8

State whether given statement is True or FalseHeat always flows from a body at lower temperature to a body at higher temperature.

Accepted Answer

Heat  energy will always be transferred from the hotter to the cooler object. The objects will exchange thermal energy, until thermal equilibrium is reached, i.e. until their temperatures are equal. We say that heat flows from the hotter to the cooler object.

Question 9

The layers of the atmosphere are heated through

Accepted Answer

The layers if the atmosphere are heated through Radiation from sun and convection currents, are responsible for heating.

Question 10

It is hotter for the same distance over the top of the fire than it is by the side is mainly because

Accepted Answer

Convection phenomena transfers heat due to the motion of medium particles as advection is a major part of convection.

Secondary Winds Land and Sea Breeze

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REVISE WITH CONCEPTS

Types of Winds

Basic Knowledge of Convection

Applications of Convection

QUICK SUMMARY WITH STORIES

Summer And Winter Monsoon

Importance Of Summer Monsoon

Sea Breeze And Land Breeze

Conduction and Convection

Convection in liquids