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Flashcards in Calorimetry And Heat Transfer. Deck (15):
1

What is the formula of q when temperature changes without change in state ?

Q= msΔ#

2

What is the formula for q when state changes without change in temperature ?

Q=mL, when state changes without change in temperature.

3

What is meant by specific heat of a substance s?

Specific heat of a substance s is the heat required to increase the temperature of unit mass by 1 C or 1K

4

What is the heat capacity of the body ?

Heat capacity of a body= ms= heat required to increase the temperature of whole body by 1 C or 1K

5

What is latent heat of a substance ?

Latent hey of a substance L is the heat required to convert unit mass of the substance from one state to another state.

6

What is meant by water equivalent of a vessel ?

Water equivalent of a vessel of the mass equivalent of water which takes same amount of heat as taken by the vessel for same rise of temperature.

7

What is absorptive power a ?

Absorptive power a = energy absorbed / energy incident.
a

8

What is spectral absorptive power aλ?

Spectral absorptive power aλ= Absoptive power of wavelength λ.

9

What is emissive power e ?

Emissive power e is the energy radiate per unit area per unit time. It's SI units are joule per second per metre square.

10

What is Stephans Law?

Emissive power of a body is given by e= e(r)σT⁴Αt.
A= Surface Area. t= time.

11

What is Kirchhoff's Law?

If different bodies (including a perfectly black body) are kept at same temperature then,
e(λ)/a(λ)=constant.

12

What are the two conclusions that can be drawn from Kirchhoff law?

1. Good absorbers are good emitters ( for a particular wavelength ).
2. Ratio (λ)/a(λ)=constant, at any given temperature. This ratio is equal to e(λ) of a perfectly black body at that temperature.

13

What is the formula of weins displacement law ?

λ(m)T=b
b=Weins constant= 2.89 x 10^-3. Further area of graph of e(λ) vs λ will give total emissive power which is proportional to T⁴.

14

What is Newtons Law of cooling?

Newtons law of cooling states that if temperature difference of a body with atmosphere is small, then rate of cooling is directly proportional to temperature difference.

15

What is the formula of Newtons Law of Cooling ?

(#₁−#₂/t)=α[((#₁+#₂)/2) - #₀]