A star can be considered as spherical ball of hot gas of radius `R`. Inside the star, the density of the gas is `rho_(r)` at radius `r` and mass of the gas within this region is `M_(r)`. The correct differential equation for variation of mass with respect to radius is (refer to the adjacent figure)A. `(dM_(1))/(dr)=A/3pirho_(r)r^(3)`B. `(dM_(r))/(dr)=4pirho_(r)r^(2)`C. `(dM_(r))/(dr)=2/3pirho_(r)r^(2)`D. `(dM_(r))/(dr)=1/3pirho_(r)r^(2)`

A star can be considered as spherical ball of hot gas of radius `R`. I

1.	A star can be considered as spherical ball of hot gas of radius `R`. Inside the star, the density of the gas is `rho_(r)` at radius `r` and mass of the gas within this region is `M_(r)`. The correct differential equation for variation of mass with respect to radius is (refer to the adjacent figure)A. `(dM_(1))/(dr)=A/3pirho_(r)r^(3)`B. `(dM_(r))/(dr)=4pirho_(r)r^(2)`C. `(dM_(r))/(dr)=2/3pirho_(r)r^(2)`D. `(dM_(r))/(dr)=1/3pirho_(r)r^(2)`
Answer» Correct Answer - B `dM_(r)=rho_(r)pir^(2)dr` `(dM_(1))/(dr)=rho_(r)4pir^(2)`

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