Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEET 2007
Exam
NEET
Year
2007
Subject
Physics
Chapter
Thermal Properties of Matter

NEET 2007 · Physics · Thermal Properties of Matter

Assuming the sun to have a spherical outer surface of radius r ,...

Assuming the sun to have a spherical outer surface of radius rr, radiating like a black body at temperature t∘Ct^{\circ} \mathrm{C}, the power received by a unit surface, (normal to the incident rays) at a distance RR from the centre of the sun is: where σ\sigma is the Stefan's constant

Options

  1. Ar2σ(t+273)44πR2\frac{r^2 \sigma(t+273)^4}{4 \pi R^2}
  2. B16π2r2σt4R2\frac{16 \pi^2 r^2 \sigma t^4}{R^2}
  3. Cr2σ(t+273)4R2\frac{r^2 \sigma(t+273)^4}{R^2}
  4. D4πr2σt4R2\frac{4 \pi r^2 \sigma t^4}{R^2}

Correct answer

C. r2σ(t+273)4R2\frac{r^2 \sigma(t+273)^4}{R^2}

Step-by-step solution

 Solar constant =σ(4πr2)T4(4πR2)=σr2(t+273)4R2\begin{aligned} \text{ Solar constant } & =\frac{\sigma\left(4 \pi r^2\right) T^4}{\left(4 \pi R^2\right)} \\ & =\frac{\sigma r^2(t+273)^4}{R^2} \end{aligned}
Practice Thermal Properties of Matter on Quantrex Academy →

More from Thermal Properties of Matter

A cylindrical rod with one end in a steam chamber and the other end in ice results in… MHT CET Medical 2026A spherical blackbody of radius 10\ m is maintained at a temperature T , radiating power… MHT CET Medical 2026The rectangular surface area (12\ cm×6\ cm) of the black body, at a temperature 127^ ^ ∘… MHT CET Medical 2026A metal sphere cools at a rate of 2^ ^ ∘ C/min when the temperature is 80^ ^ ∘ C . If the… MHT CET Medical 2026A resistance thermometer has resistance 95\ Ω at the ice point and 140\ Ω at the steam… MHT CET Medical 2026A metal sphere cools from 80^ ^ ∘ C to 60^ ^ ∘ C in 10 minute. The time taken (in minute)… MHT CET Medical 2026If the temperature of 5 kg mass of a material of a specific heat capacity 200 J/kg ^ ^ ∘… MHT CET Medical 2026The initial temperature of a body is 80^ ^ ∘ C . If its temperature falls to 64^ ^ ∘ C in… MHT CET Medical 2026 Full Thermal Properties of Matter list All NEET PYQs