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A force F=ai+3j+6k is acting at a point r=2i-6j-12k. The value of α for which angular momentum about origin is conserved is
Options
(a) 2
(b) zero
(c) 1
(d) -1
Correct Answer:
-1
Explanation:
From Newton’s second law for rotational motion,
τ = dL / dt, if L = constant then τ = 0
So, τ = r × F = 0
(2î – 6ĵ – 12k̂) × (αî + 3ĵ + 6k̂) = 0
Solving we get α = -1.
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Subject: Physics
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Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
- Electrons with energy 80 keV are incident on the tungsten target of an X-ray tube.
- In an NPN transistor the collector current is 24 mA. If 80% of the electrons
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Important MCQs Based on Medical Entrance Examinations To Improve Your NEET Score
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