Thermal Properties Of Matter

Question 1

Boyle’s law

Answer 1

When T is const, PV = const

Question 2

Charle’s law

Answer 2

When P is const, V/T = const

Question 3

R =

Answer 3

8.31 J/mol K

Question 4

Thermal expansion

Answer 4

Increase in dimensions of a body due to increase in temperature

Question 5

Linear, volume & area expansion

Answer 5

Expansion in length, volume or area

Question 6

DL/L =

Answer 6

Alpha(L) dT

Question 7

Thermal stress

Answer 7

Rod requires compressive strain due to ext forces by rigid supports at ends, in rod sets up corresponding stress

Question 8

Hear capacity

Answer 8

Change in temp of a sub when a given quantity of heat is absorbed or rejected by it

Question 9

S =

Answer 9

dQ/dT

Question 10

C =

Answer 10

1 dQ/myu dT

Question 11

s =

Answer 11

S/myu = 1 dQ/m dT

Question 12

Specific heat capacity

Answer 12

Amount if heat per unit mass absorbed or given off by the sub to raise its temperature by 1 unit.

Question 13

Specific H.C depends on

Answer 13

Nature of sub & Temp

Question 14

Later heat of fusion

Answer 14

Latent heat for solid-liquid state change

Question 15

Latent heat

Answer 15

Heat required during state change
L = Q/m

Question 16

Heat transfer modes

Answer 16

Conduction
Convection
Radiation

Question 17

Conduction

Answer 17

Transfer of heat btw adjacent parts of a body due to temperature diff

Question 18

Heat conduction

Answer 18

Time rate of heat flow in a material for a given temp diff

Question 19

Thermal conduction formula

Answer 19

H = KA(T1 - T1)/L, K is thermal conductivity of the material

Question 20

Convection

Answer 20

Heat transfer by actual motion of matter
Only possible in fluids
Can be natural or forced

Question 21

Radiation

Answer 21

Heat transfer without medium

Question 22

Radiant energy

Answer 22

Energy transferred by electromagnetic waves

Question 23

Wein’s displacement law

Answer 23

Lamda(m) T = const

Question 24

Wien’s constant value

Answer 24

2.9 × 10^-3 m K

Question 25

Stephan Boltzmann Law

Answer 25

For a body which is a perfect radiator, energy emitted = H = A sigma T⁴, sigma is Boltzmann const

Question 26

Boltzmann const value is

Answer 26

5.67 × 10^-8 W/m² K⁴

Question 27

Newton's law of cooling

Answer 27

Rate of loss of heat of a body is directly prop to diff of temp of body & surroundings -dQ/dt = k(T2 -T1), k is +ve const