1
WB JEE 2024
MCQ (Single Correct Answer)
+2
-0.5
Change Language

In a plane $$\vec{a}$$ and $$\vec{b}$$ are the position vectors of two points A and B respectively. A point $P$ with position vector $$\overrightarrow{\mathrm{r}}$$ moves on that plane in such a way that $$|\overrightarrow{\vec{r}}-\vec{a}| \sim|\vec{r}-\vec{b}|=c$$ (real constant). The locus of P is a conic section whose eccentricity is

A
$$\frac{|\vec{a}-\vec{b}|}{c}$$
B
$$\frac{|\vec{a}+\vec{b}|}{c}$$
C
$$\frac{|\vec{a}-\vec{b}|}{2 c}$$
D
$$\frac{|\vec{a}+\vec{b}|}{2 c}$$
2
WB JEE 2024
MCQ (Single Correct Answer)
+2
-0.5
Change Language

Five balls of different colours are to be placed in three boxes of different sizes. The number of ways in which we can place the balls in the boxes so that no box remains empty is

A
160
B
140
C
180
D
150
3
WB JEE 2024
MCQ (Single Correct Answer)
+2
-0.5
Change Language

Let $$A=\left(\begin{array}{ccc}1 & -1 & 0 \\ 0 & 1 & -1 \\ 1 & 1 & 1\end{array}\right), B=\left(\begin{array}{l}2 \\ 1 \\ 7\end{array}\right)$$

Then for the validity of the result $$\mathrm{AX}=\mathrm{B}, \mathrm{X}$$ is

A
$$\left(\begin{array}{c}-1 \\ 1 \\ 7\end{array}\right)$$
B
$$\left(\begin{array}{l}1 \\ 2 \\ 4\end{array}\right)$$
C
$$\left(\begin{array}{c}3 \\ 1 \\ -1\end{array}\right)$$
D
$$\left(\begin{array}{l}4 \\ 2 \\ 1\end{array}\right)$$
4
WB JEE 2024
MCQ (Single Correct Answer)
+2
-0.5
Change Language

If $$\alpha_1, \alpha_2, \ldots, \alpha_n$$ are in A.P. with common difference $$\theta$$, then the sum of the series $$ \sec \alpha_1 \sec \alpha_2+\sec \alpha_2 \sec \alpha_3+\ldots .+\sec \alpha_{n-1} \sec \alpha_n=k\left(\tan \alpha_n-\tan \alpha_1\right)$$ where $$\mathrm{k}=$$

A
$$\sin \theta$$
B
$$\cos \theta$$
C
$$\sec \theta$$
D
$$\operatorname{cosec} \theta$$
EXAM MAP