CBSE-XI-Physics
02: Physics and Mathematics
- #13If
A→×B→=0, can you say that (a) A→=B→, (b) A→≠B→?Ans : If `` \stackrel{\to }{A}\times \stackrel{\to }{B}=0``, then both the vectors are either parallel or antiparallel, i.e., the angle between the vectors is either `` 0°\mathrm{or}180°``.
(`` \stackrel{\to }{A}\stackrel{\to }{B}\mathrm{sin}\theta \vec{n}=0`` `` \because `` `` \mathrm{sin}0°=\mathrm{sin}180°=0``)
Both the conditions can be satisfied: (a) `` \stackrel{\to }{A}=\stackrel{\to }{B},`` i.e., the two vectors are equal in magnitude and parallel to each other (b) `` \stackrel{\to }{A}\ne \stackrel{\to }{B}``, i.e., the two vectors are unequal in magnitude and parallel or anti parallel to each other
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- #13-aA→=B→,Ans : `` \stackrel{\to }{A}=\stackrel{\to }{B},`` i.e., the two vectors are equal in magnitude and parallel to each other
- #13-bA→≠B→?Ans : `` \stackrel{\to }{A}\ne \stackrel{\to }{B}``, i.e., the two vectors are unequal in magnitude and parallel or anti parallel to each other
Page No 28: