A human body has a surface area of approximately 1 m^2. The normal body temperature is 10 K above the surrounding room temperature T_0. Take the room temperature to be T_0=300 K. For T_0=300 K, the value of T_0^4=460 Wm^ -2 (where is the Stefan-Boltzmann constant). Which of the following options is/are correct?

JEE Advanced 2017 Physics question

A human body has a surface area of approximately 1 m. The normal body temperature is 10 K above the surrounding room temperature . Take the room temperature to be K. For K, the value of Wm (where is the Stefan-Boltzmann constant). Which of the following options is/are correct?

(A)The amount of energy radiated by the body in 1 second is close to 60 Joules
(B)If the surrounding temperature reduces by a small amount , then to maintain the same body temperature the same (living) human being needs to radiate more energy per unit time
(C)Reducing the exposed surface area of the body (e.g. by curling up) allows humans to maintain the same body temperature while reducing the energy lost by radiationCorrect
(D)If the body temperature rises significantly then the peak in the spectrum of electromagnetic radiation emitted by the body would shift to longer wavelengths

Answer: (C)

Solution

(A) The body at 310 K radiates J every second; about 60 J is only the net loss () after the radiation absorbed from the room is subtracted: false. (B) The energy radiated depends only on the body's own temperature,

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Question ID VK-026595