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JEE Advanced 2018Paper 2
Exam
JEE Advanced
Year
2018
Paper
Paper 2
Subject
Physics
Chapter
Gravitation

JEE Advanced 2018 · Paper 2 · Physics · Gravitation

A planet of mass M, has two natural satellites with masses m _ 1...

A planet of mass M, has two natural satellites with masses m1andm2{m}_{1}and{m}_{2} . The radii of their circular orbits are R1andR2{R}_{1}and{R}_{2} respectively. Ignore the gravitational force between the satellites. Define v1,L1,K1andT1{v}_{1}, {L}_{1}, {K}_{1}and{T}_{1} to be, respectively, the orbital speed, angular momentum, kinetic energy and time period of revolution of satellite 1;andv2,L2,K2andT21; and{v}_{2}, {L}_{2}, {K}_{2}and{T}_{2} and to be the corresponding quantities of satellite 2. Given m1/m2=2andR1/R2=14{m}_{1} / {m}_{2} = 2and{R}_{1} / {R}_{2} = \dfrac{1}{4} , match the ratios in List-I to the numbers in List-II.
LIST -I LIST-II
A) v1v2\dfrac{{v}_{1}}{{v}_{2}} P) 18\dfrac{1}{8}
B) L1L2\dfrac{{L}_{1}}{{L}_{2}} Q) 1
C) K1K2\dfrac{{K}_{1}}{{K}_{2}} R) 2
D) T1T2\dfrac{{T}_{1}}{{T}_{2}} S) 8
A planet of mass M, has two natural satellites with masses m _ 1 and m _ 2 . The radii of their circular orbits are R _

Options

  1. Aa-p;b-q;c-s;d-r;
  2. Ba-s;b-p;c-r;d-q;
  3. Ca-s;b-q;c-r;d-p;
  4. Da-r;b-q;c-s;d-p;

Correct answer

D. a-r;b-q;c-s;d-p;

Step-by-step solution

A planet of mass M, has two natural satellites with masses m _ 1 and m _ 2 . The radii of their circular orbits are R _
\leftm1m2=2R1R2=14\begin{array}{ll}\dfrac{{m}_{1}}{{m}_{2}} = 2 \\ \dfrac{{R}_{1}}{{R}_{2}} = \dfrac{1}{4}\end{array}\right\} given
GMm1R12=m1V11R1\dfrac{GM{m}_{1}}{{R}_{1}^{2}} = \dfrac{{m}_{1}{V}_{1}^{1}}{{R}_{1}}
v12=GMR1,v22=GMR2{v}_{1}^{2} = \dfrac{GM}{{R}_{1}}, {v}_{2}^{2} = \dfrac{GM}{{R}_{2}}
v12v22=R2R1=4\dfrac{{v}_{1}^{2}}{{v}_{2}^{2}} = \dfrac{{R}_{2}}{{R}_{1}} = 4
\left(i\right)v1v2=2\dfrac{{v}_{1}}{{v}_{2}} = 2
\left(ii\right)L=mvRL = mvR
L1L2=m1v1R1m2v2R2=2×2×14=1\dfrac{{L}_{1}}{{L}_{2}} = \dfrac{{m}_{1}{v}_{1}{R}_{1}}{{m}_{2}{v}_{2}{R}_{2}} = 2 \times 2 \times \dfrac{1}{4} = 1
\left(iii\right)K=12mv2K = \dfrac{1}{2}m{v}^{2}
K1K2=m1v12m2v22=2×(2)2=8\dfrac{{K}_{1}}{{K}_{2}} = \dfrac{{m}_{1}{v}_{1}^{2}}{{m}_{2}{v}_{2}^{2}} = 2 \times {\left(2\right)}^{2} = 8
(iv)( iv ) $T = 2\piR / V
\dfrac{{T}_{1}}{{T}_{2}} = \dfrac{{R}_{1}}{{v}_{1}} \times \dfrac{{v}_{2}}{{R}_{2}} = \dfrac{{R}_{1}}{{R}_{2}} \times \dfrac{{v}_{2}}{{v}_{1}} = \dfrac{1}{4} \times \dfrac{1}{2} = \dfrac{1}{8}
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