Question: For a white body, absorptivity (α ) = 0, reflectivity (ρ) = 1 and transmittivity (τ) = 0.
[A].Correct
Incorrect
[A].
[B].
Answer: Option A
Explanation:
No answer description available for this question.
An infinite parallel planes with emissivities e1 and e2, the interchange factor for radiation from surface 1 to surface 2 is given by
Question: An infinite parallel planes with emissivities e1 and e2, the interchange factor for radiation from surface 1 to surface 2 is given by
[A].e1 + e2
e1e2
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.
A grey body is one whose absorptivity does not vary with temperature and wave length of the incident ray.
Question: A grey body is one whose absorptivity does not vary with temperature and wave length of the incident ray.
[A].True
False
[A].
[B].
Answer: Option A
Explanation:
No answer description available for this question.
Emissivity of a body will be equal to its absorptivity at all temperatures.
Question: Emissivity of a body will be equal to its absorptivity at all temperatures.
[A].Yes
No
[A].
[B].
Answer: Option B
Explanation:
No answer description available for this question.
ODOMETER : DISTANCE
Question: ODOMETER : DISTANCE
[A].scale : weight
length : width
inch : foot
mileage : speed
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
Scale – A measuring instrument for weighing; shows amount of mass.
An odometer measures distance; a scale measures weight.
If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called
Question: If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called
[A].absorptive power
emissive power
emissivity
none of these
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
A perfect black body is one which
Question: A perfect black body is one which
[A].is black in colour
absorbs heat radiations of all wave lengths falling on it
reflects all the heat radiations
transmits the heat radiations
[A].
[B].
[C].
[D].
Answer: Option B
Explanation:
No answer description available for this question.
The amount of radiation mainly depends upon the
Question: The amount of radiation mainly depends upon the
[A].nature of the body
temperature of the body
type of surface of the body
all of these
[A].
[B].
[C].
[D].
Answer: Option D
Explanation:
No answer description available for this question.
Nusselt number (NN) is given by
Question: Nusselt number (NN) is given by
[A].
[A].
[B].
[C].
[D].
Answer: Option A
Explanation:
No answer description available for this question.
In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the
Question: In free convection heat transfer transition from laminar to turbulent flow is governed by the critical value of the
[A].Reynold’s number
Grashoff’s number
Reynold’s number, Grashoff’s number
Prandtl number, Grashoff’s number
[A].
[B].
[C].
[D].
Answer: Option D
Explanation:
No answer description available for this question.