EASY
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If A ,   B  and C are the unit vectors along the incident ray, reflected ray and outward normal to the reflecting surface, then

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Important Questions on Vector Algebra

EASY
Let a=2i^+λ1j^+3k^, b=4i^+3-λ2j^+6k^ and c=3i^+6j^+λ3-1k^ be three vectors such that b=2a and a is perpendicular to c. Then a possible value of λ1, λ2, λ3 is
MEDIUM
If the sum of two unit vectors is again a unit vector, then magnitude of their difference is
EASY
If A=3i^-2j^+k^B=i^-3j^+5k^ and  C=2i^+j^-4k^ form a right angled triangle then out of the following which one is satisfied?
HARD
If the vectors AB=3i^+4k^ and AC=5i^-2j^+4k^ are the sides of a triangle ABC, then the length of the median through A is:
HARD

In a triangle PQR , let a=QR, b=RP and c=PQ .

If a =3, b =4 and a.cbc.ab=aa+b, then the value of a×b2 is _______

EASY
If vectors A=cosωi^+sinωt j^ and B=cosωti^+sinωtj^ are functions of time, then the value of t at which they are orthogonal to each other is:
EASY
The diagonals of a parallelogram are the vectors 3i^+6j^-2k^ and -i^-2j^-8k^ then, the length of the shorter side of parallelogram is
MEDIUM
The area (in sq. units) of the parallelogram whose diagonals are along the vectors 8i^-6j^ and 3i^+4j^-12k^, is:
EASY
In a ABC, D, E, F are the mid-points of the sides BCCA and AB respectively, the vector AD is equal to
MEDIUM
Let u and v be two vectors. Then, u-v=|u-v| if and only if
MEDIUM
In a parallelogram ABCD, AB=a, AD=b & AC=cDB·AB has the value:
HARD
Let PR=3i^+j^-2k^&SQ=i^-3j^-4k^ determine diagonals of a parallelogram PQRS and PT=i^+2j^+3k^ be another vector. Then the volume (in cubic unit) of the parallelepiped determined by the vectors PT, PQ & PS  is
EASY
Let A=i^ + j^ and B=(2i^- j^) . The magnitude of a coplanar vector C such that A . C=B. C= A . B is given by:
HARD
Let a=i^+j^+2k^, b=b1i^+b2j^+2k^ and  c=5i^+j^+2k^ be three vectors such that the projection vector of b on a is a . If a+b is perpendicular to c , then b is equal to:
HARD

Given, a=2i^+j^-2k^ and b= i^+j^. Let c be a vector such that c- a=3, a×b×c=3 and the angle between c and a×b be 30° . Then ac is equal to:

HARD
If a=2, b=3 and 2a-b=5, then 2a+b equals :
HARD
If the vector b=3j^+4k^ is written as the sum of a vector b1, parallel to a= i^+ j^ and a vector b2, perpendicular to a, then b1×b2 is equal to :
MEDIUM
The two vectors i^+j^+k^ and i^+3j^+5k^ represent the two sides AB and AC respectively of a ΔABC. The length of the median through A is
MEDIUM
 If a and b are unit vectors, then the greatest value of 3|a+b|+|a-b| is
 
HARD
Let v be a vector in the plane such that |v-i|=|v-2i|=|v-j|. Then |v| lies in the interval.