Skip to main content

A B C is a triangle, right angled at A. The resultant of the forces acting along overrightarrowA B, overrightarrowA C with magnitudes 1 A B and 1 A C…

JEE Main 2006 — Mathematics Vectors & 3D Geometry

2006mcqeasy

ABCA B CABC is a triangle, right angled at AAA. The resultant of the forces acting along AB→,AC→\overrightarrow{A B}, \overrightarrow{A C}AB,AC with magnitudes 1AB\frac{1}{A B}AB1​ and 1AC\frac{1}{A C}AC1​ respectively is the force along AD→\overrightarrow{A D}AD, where DDD is the foot of the perpendicular from A\mathrm{A}A onto BC\mathrm{BC}BC. The magnitude of the resultant is

Official previous-year question

Held on 30 Apr 2006 · Verified 6 Jul 2026.

Options

  1. A

    AB2+AC2(AB)2(AC)2\frac{A B^2+A C^2}{(A B)^2(A C)^2}(AB)2(AC)2AB2+AC2​

  2. B

    (AB)(AC)AB+AC\frac{(A B)(A C)}{A B+A C}AB+AC(AB)(AC)​

  3. C

    1AB+1AC\frac{1}{A B}+\frac{1}{A C}AB1​+AC1​

  4. D

    1AD\frac{1}{\mathrm{AD}}AD1​

Did you get this right?

Sign in to track your attempts and accuracy.

Your note

Sign in to keep a private note on this question. Nothing you write is ever public.

JEE Main Vectors & 3D Geometry in other years

More JEE Main Vectors & 3D Geometry questions

Let $\hat{u}$ and $\hat{v}$ be unit vectors inclined at an acute angle such that $|\hat{u}\times\hat{v}|=\dfrac{\sqrt{3}}{2}$. If $\vec{A}=\lambda\hat{u}+\hat{v}+(\hat{u}\times\hat{v})$, then $\lambda$ is equal to:

2026medium

Let $\vec{a}, \vec{b}, \vec{c}$ be three vectors such that $\vec{a} \times \vec{b}=2(\vec{a} \times \vec{c})$. If $|\vec{a}|=1,|\vec{b}|=4,|\vec{c}|=2$, and the angle between $\vec{b}$ and $\vec{c}$ is $60^{\circ}$, then $|\vec{a} \cdot \vec{c}|$ is equal to

2026medium

If the distances of the point $(1,2, a)$ from the line $\frac{x-1}{1}=\frac{y}{2}=\frac{z-1}{1}$ along the lines $\mathrm{L}_{1}: \frac{x-1}{3}=\frac{y-2}{4}=\frac{z-a}{b}$ and $\mathrm{L}_{2}: \frac{x-1}{1}=\frac{y-2}{4}=\frac{z-a}{c}$ are equal, then $a+b+c$ is equal to

2026hard

If the distance of the point $\mathrm{P}(43, \alpha, \beta), \beta<0$, from the line $\overrightarrow{\mathrm{r}}=4 \hat{i}-\hat{k}+\mu(2 \hat{i}+3 \hat{k}), \mu \in \mathbf{R}$ along a line with direction ratios $3,-1,0$ is $13 \sqrt{10}$, then $\alpha^{2}+\beta^{2}$ is equal to $\_\_\_\_$

2026hard

Let $\overrightarrow{\mathrm{AB}}=2 \hat{i}+4 \hat{j}-5 \hat{k}$ and $\overrightarrow{\mathrm{AD}}=\hat{i}+2 \hat{j}+\lambda \hat{k}, \lambda \in \mathbb{R}$. Let the projection of the vector $\vec{v}=\hat{i}+\hat{j}+\hat{k}$ on the diagonal $\overrightarrow{\mathrm{AC}}$ of the parallelogram ABCD be of length one unit. If $\alpha, \beta$, where $\alpha>\beta$, be the roots of the equation $\lambda^{2} x^{2}-6 \lambda x+5=0$, then $2 \alpha-\beta$ is equal to

2026hard

Other Mathematics topics for JEE Main

Keep practicing Vectors & 3D Geometry

Work through every JEE Main Vectors & 3D Geometry PYQ, year by year.

Browse all Mathematics topics