If a = i - 2j and b = 2i + j are parallel, then is - Vidyadip

MCQ

If $a = i - 2j$ and $b = 2i + \lambda j$ are parallel, then $\lambda $ is

A
$4$
B
$2$
C
$-2$
✓
$-4$

✓

Answer

Correct option: D.

$-4$

d
(d) $\frac{1}{2} = \frac{{ - 2}}{\lambda } \Rightarrow \lambda = - 4$.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from STD 12 - 10. vector algebra→STD 12 - 10. vector algebra — all question types→Mathematics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

If $f:[0,\;\infty ) \to [0,\;\infty )$ and $f(x) = \frac{x}{{1 + x}},$ then $f$ is

If $A = \int\limits_1^{\sin \theta } {\frac{t}{{1 + {t^2}}}} dt$ and $B = \int\limits_1^{\cos ec\theta } {\frac{dt}{{t\left( {1 + {t^2}} \right)}}} $ , (where $\theta \in \left( {0,\frac{\pi }{2}} \right))$, then the-value of $\left| {\begin{array}{*{20}{c}}
A&{{A^2}}&{ - B}\\
{{e^{A + B}}}&{{B^2}}&{ - 1}\\
1&{{A^2} + {B^2}}&{ - 1}
\end{array}} \right|$ is

Let $A$ be a $2 \times 2$ real matrix and $I$ be the identity matrix of order $2$ . If the roots of the equation $|A-x I|=0$ be $-1$ and $3$ , then the sum of the diagonal elements of the matrix $A^2$ is$..............$

If $A$ and $B$ are symmetric matrices of the same order, then

If $\text{f}\ '(\text{x})=\text{x}+\frac{1}{\text{x}},$ then value of $f(x)$ is:

A six faced die is biased such that $3 \times P ($ a prime number $)=6 \times P ($ a composite number $)=2 \times P (1)$.Let $X$ be a random variable that counts the number of times one gets a perfect square on some throws of this die. If the die is thrown twice, then the mean of $X$ is.

Let $A (2, 3, 5), B (- 1, 3, 2)$ and $C (\lambda, 5, \mu)$ be the vertices of a $\Delta ABC$. If the median through $A$ is equally inclined to the coordinate axes, then

The differential equation $y\frac{{dy}}{{dx}} + x = a$($a$ is any constant) represents

If $A$ and $B$ are two events such that $P(A \cup B)=\frac{5}{6}, P(A \cap B)=\frac{1}{3}$ and $P(\bar{B})=\frac{1}{2}$ then the events $A$ and $B$ are

Choose the correct answer from the given four option.The general solution of $\text{e}^{\text{x}}\cos\text{ydx}-\text{e}^\text{x}\sin\text{ydy}=0$ is: