Consider a star of mass m_2 ~kg revolving in a circular orbit around another star of mass m_1 ~kg with m_1 m_2. The heavier star slowly acquires mass from the lighter star at a constant rate of kg / s . In this transfer process, there is no other loss of mass. If the separation between the centers o

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Consider a star of mass m_2 ~kg revolving in a circular orbit around another star of mass m_1 ~kg with m_1 m_2. The heavier star slowly acquires mass from the lighter star at a constant rate of kg / s . In this transfer process, there is no other loss of mass. If the separation between the centers of the stars is r, then its relative rate of change 1 r ~d r ~d t ( . in s .^ -1 ) is given by: [Note: The original question was awarded bonus marks in the JEE Advanced 2025 exam. We have changed the options to make the question valid and solvable.]

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Correct answer: B. 2 3 m_2

$ aligned & v=v_0= G m_1 r \ & d v_0 d t = v_0 2 [ m_1 - 1 r d r d t ] aligned $ $ aligned & F =m_2 d v d t \ & G m_1 r^2 v_r v = d v d t \ & v_0 r d r d t 1 v_0 = d v d t aligned $ $ V_0 d d t = X_0 2 [ r m_1 - 1 r d r d t ]$ $ 3 2 1 d d t = r 2 m_1 1 d r d t = 3 m_2 $

JEE Advanced Physics Question (2025) — Solution

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