Question

The mass of the sun is approximately $2\times {10}^{30}$kg. The Schwarzschild radius for the mass of a star that is ten times the mass of the sun is nearly

• A. 3km
• B. 30km
• C. 300 km
• D. 0.3km

Answer 1

The correct option is B 30km

Schwarzschild radius is given by
$R=\frac{2GM}{C^2}=\frac{2\times 6.67\times {10}^{-11}\times 10\times 2\times {10}^{30}}{9\times {10}^{16}}=\frac{4\times 6.67}{9}\times {10}^4=2.9644\times {10}^{4}m=29.644$km
Option B.