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Vector Algebra question

2022 · 25 Jun · Shift 1 · Q34

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PYQ Library
JEE Main
Mathematics
Vector Algebra
2022 · 25 Jun · Shift 1 · Q34

Vector Algebra question

2022 · 25 Jun · Shift 1 · Q34

JEE MainMathematicsVector AlgebraMCQ+4 / −1

Let

\overrightarrow a = {a_1}\widehat i + {a_2}\widehat j + {a_3}\widehat k

{a_i} \gt 0

,

i = 1,2,3

be a vector which makes equal angles with the coordinate axes OX, OY and OZ. Also, let the projection of

\overrightarrow a

on the vector

3\widehat i + 4\widehat j

be 7. Let

\overrightarrow b

be a vector obtained by rotating

\overrightarrow a

with 90

^\circ

. If

\overrightarrow a

,

\overrightarrow b

and x-axis are coplanar, then projection of a vector

\overrightarrow b

on

3\widehat i + 4\widehat j

is equal to:

A
$\sqrt 7$
B
$\sqrt 2$
C
2
D
7

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