Flashcards in Calorimetry And Heat Transfer. Deck (15):
What is the formula of q when temperature changes without change in state ?
What is the formula for q when state changes without change in temperature ?
Q=mL, when state changes without change in temperature.
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
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
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.
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.
What is absorptive power a ?
Absorptive power a = energy absorbed / energy incident.
What is spectral absorptive power aλ?
Spectral absorptive power aλ= Absoptive power of wavelength λ.
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.
What is Stephans Law?
Emissive power of a body is given by e= e(r)σT⁴Αt.
A= Surface Area. t= time.
What is Kirchhoff's Law?
If different bodies (including a perfectly black body) are kept at same temperature then,
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.
What is the formula of weins displacement law ?
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.
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.