The value of (A+B) (A-B) is - Vidyadip

MCQ

The value of $(\vec{A}+\vec{B}) \times(\vec{A}-\vec{B})$ is

B
$A^2-B^2$
C
$\vec{B} \times \vec{A}$
✓
$2(\vec{B} \times \vec{A})$

✓

Answer

Correct option: D.

$2(\vec{B} \times \vec{A})$

(d)$\begin{aligned}& (\vec{A}+\vec{B}) \times(\vec{A}-\vec{B})=\vec{A} \times \vec{A}-\vec{A} \times \vec{B}+\vec{B} \times \vec{A}-\vec{B} \times \vec{B} \\& =0-\vec{A} \times \vec{B}+\vec{B} \times \vec{A}-0=\vec{B} \times \vec{A}+\vec{B} \times \vec{A}=2(\vec{B} \times \vec{A})\end{aligned}$

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 "MCQ" from Vector→Vector — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

The gravitational field due to a mass distribution is $E=K / x^3$ in the $x$-direction. ( $K$ is a constant). Taking the gravitational potential to be zero at infinity, its value at a distance $x$ is

A body of mass $M$ moves with velocity $v$ and collides elastically with a another body of mass $m(M>m)$ at rest then the velocity of body of mass $m$ is

The length of the wire is doubled. Its conductance will be

The electromagnetic waves do not transport

A measure of the degree of disorder of a system is known as

A black body at a temperature of $127^{\circ} \mathrm{C}$ radiates heat at the rate of $1 \mathrm{cal} / \mathrm{cm} \times \mathrm{sec}$. At a temperature of $527^{\circ} \mathrm{C}$ the rate of heat radiation from the body in $(\mathrm{cal} / \mathrm{cm} \times \mathrm{sec})$ will be

A proton and an $\alpha$-particle are accelerated through a potential difference of $100 \mathrm{~V}$. The ratio of the wavelength associated with the proton to that associated with an $\alpha$-particle is

If radius of the earth contracts $2 \%$ and its mass remains the same, then weight of the body at the earth surface

If the amount of heat given to a system be 35 joules and the amount of work done by the system be -15 joules, then the change in the internal energy of the system is

A conducting wire is dropped along east-west direction, then