1. Unit of thermal conductivity in S.I. units is
A.J/m2 sec
B.J/m °K sec
C.W/m °K
D.(B) and (C) above
2. Thermal conductivity of solid metals with rise in temperature normally
A.Increases
B.Decreases
C.Remains constant
D.May increase or decrease depending on temperature
3. In heat transfer, conductance equals conductivity (kcal/hr/sqm/°C/cm) divided by
A.HR (time)
B.SQM (area)
C.°C (temperature)
D.CM (thickness)
4. Heat transfer takes place as per
A.Zeroth law of thermodynamics
B.First law of thermodynamics
C.Second law of the thermodynamics
D.Kirchoff's law
5. Depending on the radiating properties, a black body will be black when
A.ρ = 0, τ = 0 and α = 1
B.ρ = 1, τ = 0 and α = 0
C.ρ = 0, τ = 1 and α = 0
D.τ = 0, α+ρ = 1
6. According to planck's law, the wavelength corresponding to the maximum energy is proportional to
A.Absolute temperature T
B.T2
C.T4
D.1/T
7. When heat is transferred form hot body to cold body, in a straight line, without affecting the intervening medium, it is referred to as heat transfer by
A.Conduction
B.Convection
C.Radiation
D.Conduction and convection
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