The total radiant energy per unit area, normal to the direction of incidence, received at a distance R from the centre of a star of

Q: The total radiant energy per unit area, normal to the direction of incidence, received at a distance $R$ from the centre of a star of radius $r$, whose outer surface radiates as a black body at a temperature $T\ K$ is given by

a According to the Stefan Boltzmann law, the power radiated by the star whose surface radiates as a black body at temperature $T\,K$ is given by $P = \sigma 4\pi {r^2}{T^4}$ Where, $r=radius\,of\,the\,star$ $\sigma=Stefan's\,constant$ The radiant power per unit area received at a distance $R$ from the centre of a star is $S = \frac{P}{{4\pi {R^2}}} = \frac{{\sigma 4\pi {r^2}{T^4}}}{{4\pi {R^2}}} = \frac{{\sigma {r^2}{T^4}}}{{{R^2}}}$

SECTION - A [PHYSICS - MCQ]

GSEB - English Medium

The total radiant energy per unit area, normal to the direction of incidence, received at a distance $R$ from the centre of a star of radius $r$, whose outer surface radiates as a black body at a temperature $T\ K$ is given by

A$\sigma \frac{{{r^2}}}{{{R^2}}}{T^4}$
B$\frac{{\sigma {r^2}}}{{4\pi {R^2}}}{T^4}$
C$\;\sigma \frac{{{r^4}}}{{{R^4}}}{T^4}$
D$\;\sigma \frac{{4\pi {r^2}}}{{{R^2}}}{T^4}$

AIPMT 2010, Medium

STD 11 Science
NEET
STD 11 - 10.2. transmission of heat
Physics

Download our app
and get started for free

Experience the future of education. Simply download our apps or reach out to us for more information. Let's shape the future of learning together!No signup needed.*

Download App

Similar Questions

1
A black body at a temperature of $1640\,\,K$ has the wavelength corresponding to maximum emission equal to $1.75 \,\,\mu m.$ Assuming the moon to be a perfectly black body, the temperature of the moon, if the wavelength corresponding to maximum emission is $14.35\,\,\mu m$ is.......$K$
View Solution
2
Two spheres of different materials one with double the radius and one-fourth wall thickness of the other, are filled with ice. If the time taken for complete melting ice in the large radius one is $25$ minutes and that for smaller one is $16$ minutes, the ratio of thermal conductivities of the materials of larger sphere to the smaller sphere is
View Solution
3
Newton's law of cooling is used in laboratory for the determination of the
View Solution
4
The temperature of sun is $5500 K$ and it emits maximum intensity radiation in the yellow region $(5.5 \times {10^{ - 7}}m)$. The maximum radiation from a furnace occurs at wavelength $11 \times {10^{ - 7}}m.$The temperature of furnace is ....... $K$
View Solution
5
The temperature $\theta$ at the junction of two insulating sheets, having thermal resistances $R _{1}$ and $R _{2}$ as well as top and bottom temperatures $\theta_{1}$ and $\theta_{2}$ (as shown in figure) is given by
View Solution
6
If the temperature of the sun becomes twice its present temperature, then
View Solution
7
A black body radiates energy at the rate of $1 \times 10^5 J / s \times m^2$ at temperature of $227^o C$. The temperature to which it must be heated so that it radiates energy at rate of $1 \times 10^9J/s m^2$, is
View Solution
8
If $\lambda_{ m }$ denotes the wavelength at which the radioactive emission from a black body at a temperature $T \;K$ is maximum, then
View Solution
9
If the temperature of a black body be increased from ${27^o}C$ to ${327^o}C$ the radiation emitted increases by a fraction of
View Solution
10
The coefficient of thermal conductivity depends upon
View Solution

Download our appand get started for free

Similar Questions

Download our app
and get started for free