Question

The distance of the Sun from earth is $1.5 \times 10^{11}\, m$ and its angular diameter is $(2000) \,s$ when observed from the earth. The diameter of the Sun will be :

• A. $2.45 \times 10^{10}\, m$
• B. $1.45 \times 10^{10}\, m$
• C. $1.45 \times 10^{9} \,m$
• D. $0.14 \times 10^{9} \,m$

Answer 1

Answer: (C)

$\frac{2000}{60 \times 60} \times \frac{\pi}{180}=\frac{ d }{1.5 \times 10^{\prime \prime}}$
$\Rightarrow d =\frac{2000}{60 \times 60} \times \frac{\pi}{180} \times 1.5 \times 10^{\prime \prime}$
$=\frac{\pi \times 1.5}{3 \times 6 \times 18} \times 10^{\prime \prime}=1.45 \times 10^{9}$