Question
A particle of mass m moves in the XY plane with a velocity v along the straight line AB. If the angular momentum of the particle with respect to origin O is LA when it is at A and LB when it is B, then: 
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LA > LB
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LA = LB
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the relationship between LA and LB depends upon the slope of the line AB
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LA < LB
Solution
B.
LA = LB
From the definition of angular momentum,
Therefore, the magnitude of L is
L = mvr sin Φ = mvd
where d = r sin Φ is the distance of closest approach of the particle so the origin. As d is same for both the particles, hence, LA = LB
