2) Thermal Physics

Question 1

Define Brownian motion

Answer 1

It is the random movement of larger particles, due to their collision with faster moving, smaller particles.

Question 2

Define Absolute scale of temperature

Answer 2

A temperature scale, whose 00C is equivalent to -273.15 °C (absolute zero) and whose 373.150C is equivalent to 1000C.

Question 3

Define Absolute zero

Answer 3

Absolute zero is the temperature at which a thermodynamic system has the lowest energy. This temperature corresponds to -273.150C on a Celsius temperature scale.

Question 4

State Boyle’s law

Answer 4

For a fixed mass of a gas at constant temperature, the volume varies inversely as the pressure. Hence pv=constant; where p=pressure on the gas and v=volume of the gas.

Question 5

Define Thermal expansion

Answer 5

Thermal expansion is the expansion of an object under the influence of heat

Question 6

Define Specific heat capacity

Answer 6

It is the amount of heat energy , needed to raise the temperature of unit mas of a substance through 10C

Question 7

Define Melting point:

Answer 7

t is the temperature at which a solid changes into a liquid

Question 8

Define Boiling point:

Answer 8

It is the temperature at which a liquid changes into a gas, without a rise in temperature.

Question 9

Define Evaporation:

Answer 9

It is the temperature at which a liquid changes into a gas, over a range of temperatures

Question 10

Define Good thermal conductors

Answer 10

Substances that allow the heat energy to flow through them easily are called as good thermal conductors.

Question 11

Define Bad thermal conductors ( good thermal insulators):

Answer 11

Substances that do not allow the heat energy to flow through them easily are called as good thermal insulators.

Question 12

Define Conduction

Answer 12

Conduction is the the transfer of energy through the movement of particles that are touching each other.

Question 13

Define Convection

Answer 13

Convection is a process of heat transfer involving density differences within molecules of the same fluid , in which the warmer and less dense portions rise up, while the more dense and the heavier ones sink down.

Question 14

Define Radiation:

Answer 14

adiation refers to the process of transmission or emission of energy in the form of waves that can travel through vacuum, meaning they do not require any medium.