NEET Keplers Law MCQs & PYQs

Practice NEET Keplers Law Questions

Question 11:

moderate

A satellite A of mass $m$ is at a distance of $r$ from the surface of the earth. Another satellite B of mass $2m$ is at a distance of $2r$ from the earth’s centre. Their time periods are in the ratio of:

(1993)

Time period of a satellite is independent of its mass. Assuming the distance $r$ for satellite A was intended to be from the centre (a standard typo in this question format), $r_A = r$ and $r_B = 2r$. Their time period ratio $\frac{T_A}{T_B} = \left(\frac{r_A}{r_B}\right)^{3/2} = \left(\frac{1}{2}\right)^{3/2} = 1:2\sqrt{2}$.

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Question 12:

moderate

The largest and the shortest distance of the earth from the sun are $r_1$ and $r_2$. Its distance from the sun when it is at perpendicular to the major axis of the orbit drawn from the sun is:

(1988)

The distance from the sun when the planet is perpendicular to the major axis drawn from the sun is the semi-latus rectum of the elliptical orbit. It is calculated as the harmonic mean of the apoapsis and periapsis distances, giving $\frac{2r_1r_2}{r_1+r_2}$.

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