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The total emissivity power is defined as the total amount of radiation emitted by a black body per unit

A. Temperature

B. Thickness

C. Area

D. Time

Answer: Option C

Solution (By Examveda Team)

Total emissive power refers to the total amount of thermal radiation emitted by a surface (typically a black body) across all wavelengths per unit time and per unit area.

This concept is governed by Stefan-Boltzmann law, which states:

E = σT⁴

Where:
E = Total emissive power
σ = Stefan-Boltzmann constant
T = Absolute temperature of the black body

As per the definition, the total emissive power is expressed in units of watts per square meter (W/m²), indicating that it is radiation emitted per unit area.

Therefore, the correct answer is: Area (Option C).

This Question Belongs to Mechanical Engineering >> Heat And Mass Transfer

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Comments (5)

  1. Ayaz Ali
    Ayaz Ali:
    2 months ago

    The total amount of thermal radiation emitted by a surface per unit area per unit time
    Correct ans is unit Area

  2. Kashif Alim
    Kashif Alim:
    4 years ago

    Area and time both

  3. Deep Pakawala
    Deep Pakawala:
    5 years ago

    Area and time both

  4. Odisha Free
    Odisha Free:
    5 years ago

    Time

  5. Sarveshwer Chandra
    Sarveshwer Chandra:
    5 years ago

    Time

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