MCQ
An earth satellite $X$ is revolving around earth in an orbit whose radius is one-fourth of the radius of orbit of a communication satellite. Time period of revolution of $X$ is ..........
- ✓$3 \,hrs$
- B$6 \,hrs$
- C$4 \,days$
- D$72 \,days$
✓
Answer
Correct option: A.
$3 \,hrs$
a
(a)
(a)
Time period of a communication satellite $=24$ hours.
Using kepler's third law,
$T^2 \propto r^3$
$\Rightarrow \frac{T_c}{T_x}=\left(\frac{r_c}{r_x}\right)^{3 / 2}$
$\Rightarrow \frac{24}{T_x}=(4)^{3 / 2}$
$\Rightarrow T_x=\frac{24}{8}=3 \,hrs$
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