# Test: Spectral And Spatial Energy Distribution

## 10 Questions MCQ Test Heat Transfer for Engg. | Test: Spectral And Spatial Energy Distribution

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This mock test of Test: Spectral And Spatial Energy Distribution for Chemical Engineering helps you for every Chemical Engineering entrance exam. This contains 10 Multiple Choice Questions for Chemical Engineering Test: Spectral And Spatial Energy Distribution (mcq) to study with solutions a complete question bank. The solved questions answers in this Test: Spectral And Spatial Energy Distribution quiz give you a good mix of easy questions and tough questions. Chemical Engineering students definitely take this Test: Spectral And Spatial Energy Distribution exercise for a better result in the exam. You can find other Test: Spectral And Spatial Energy Distribution extra questions, long questions & short questions for Chemical Engineering on EduRev as well by searching above.
QUESTION: 1

### The distribution of radiant energy is non uniform with respect to

Solution:

It should be non-uniform with respect to both wavelength and direction.

QUESTION: 2

### “Spatial distribution is also known as directional distribution”. Choose the correct option

Solution:

Spatial or directional both are same.

QUESTION: 3

### Of the radiant energy 350W/m2 incident upon a surface 250W/m2 is absorbed, 60W/m2 is reflected and the remainder is transmitted through the surface. Workout the value for absorptivity for the surface material

Solution:

Absorptivity = 250/350 = 0.714.

QUESTION: 4

Thermal radiation strikes a surface which has a reflectivity of 0.55 and transmissivity of 0.032. A quantity known as flux is found out to be 95 W/m 2. Determine the rate of incident flux.

Solution:

Incident flux = 95/1 – 0.032 – 0.55 = 227.27 W/m2.

QUESTION: 5

What is the wavelength for visible light?

Solution:

This is the maximum and minimum wavelength for visible light.

QUESTION: 6

Radiant energy with an intensity of 800 W/m2 strikes a flat plate normally. The absorptivity is thrice the reflectivity and twice the transmissivity. Determine the rate of absorption

Solution:

Rate of absorption = 0.5455 * 800 = 436.40 W/m2.

QUESTION: 7

A thin metal plate of 4 cm diameter is suspended in atmospheric air whose temperature is 290 K. This plate attains a temperature of 295 K when one of its face receives radiant energy from a heat source at the rate of 2 W. If heat transfer coefficient on both surfaces of the plate is stated to be 87.5 W/m 2 K, workout the reflectivity of the plate

Solution:

Heat loss by convection from both sides of the plates = 2 h A d t = 1.1 W. Energy lost by reflection = 2.0 – 1.1 = 0.9 W.

QUESTION: 8

On clear night there is radiation from earth’s surface to the space. On such a night, the water particles on the plant leaves radiate to the sky whose temperature may be taken as 200 K. The water particles receive heat by convection from the surrounding air, the convection heat transfer coefficient has a value of 30 W/m2 K. If the water should not freeze, make calculations for the air temperature

Solution:

Heat radiated to sky = Heat received by convection. So, temperature of air = 224.22/30 + 273 = 280.474 K.

QUESTION: 9

“Isothermal furnaces, with small apertures, approximate a black body and are frequently used to calibrate heat flux gauges”. Chose the correct answer

Solution:

A small hole leading into a cavity thus acts very nearly as a black body.

QUESTION: 10

A surface element emits radiation in all directions, the intensity of radiation is however same in different directions. Choose the correct answer

Solution:

It must be different in different directions.