1
IIT-JEE 1994
+4
-1
Let $$\overrightarrow p$$ and $$\overrightarrow q$$ be the position vectors of $$P$$ and $$Q$$ respectively, with respect to $$O$$ and $$\left| {\overrightarrow p } \right| = p,\left| {\overrightarrow q } \right| = q.$$ The points $$R$$ and $$S$$ divide $$PQ$$ internally and externally in the ratio $$2:3$$ respectively. If $$OR$$ and $$OS$$ are perpendicular then
A
$$9{q^2} = 4{q^2}$$
B
$$4{p^2} = 9{q^2}$$
C
$$9p = 4q$$
D
$$4p = 9q$$
2
IIT-JEE 1993
+1
-0.25
Let $$a, b, c$$ be distinct non-negative numbers. If the vectors $$a\widehat i + a\widehat j + c\widehat k,\widehat i + \widehat k$$ and $$c\widehat i + c\widehat j + b\widehat k$$ lie in a plane, then $$c$$ is
A
the Arithmetic Mean of $$a$$ and $$b$$
B
the Geometric Mean of $$a$$ and $$b$$
C
the Harmonic Mean of $$a$$ and $$b$$
D
equal to zero
3
IIT-JEE 1988
+2
-0.5
Let $$\overrightarrow a ,\overrightarrow b ,\overrightarrow c ,$$ be three non-coplanar vectors and $$\overrightarrow p ,\overrightarrow q ,\overrightarrow r,$$ are vectors defined by the relations $$\overrightarrow p = {{\overrightarrow b \times \overrightarrow c } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}},\,\,\overrightarrow q = {{\overrightarrow c \times \overrightarrow a } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}},\,\,\overrightarrow r = {{\overrightarrow a \times \overrightarrow b } \over {\left[ {\overrightarrow a \overrightarrow b \overrightarrow c } \right]}}$$ then the value of the expression $$\left( {\overrightarrow a + \overrightarrow b } \right).\overrightarrow p + \left( {\overrightarrow b + \overrightarrow c } \right).\overrightarrow q + \left( {\overrightarrow c + \overrightarrow a } \right),\overrightarrow r$$ is equal to
A
$$0$$
B
$$1$$
C
$$2$$
D
$$3$$
4
IIT-JEE 1987
+2
-0.5
The number of vectors of unit length perpendicular to vectors $$\overrightarrow a = \left( {1,1,0} \right)$$ and $$\overrightarrow b = \left( {0,1,1} \right)$$ is
A
one
B
two
C
three
D
infinite
EXAM MAP
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