Home
Class 12
PHYSICS
If the two vectors vec(A)=2hat(i)+3hat(j...

If the two vectors `vec(A)=2hat(i)+3hat(j)+4hat(k) and vec(B)=hat(i)+2hat(j)-nhat(k)` are perpendicular then the value of n is :

A

1

B

2

C

3

D

4

Text Solution

Verified by Experts

The correct Answer is:
B
The scalar product of two vector.s is
`" "vec(A)*vec(B)=Abcostheta`
When `theta=90^(@)`, then `cos90^(@)=0`
`" "vec(A)*vec(B)=0`
`" "(2i+3hat(j)+4hat(k))*(hat(i)+2hat(j)-nhat(k))=0`
`rArr" "2+6-4n=0`
`rArr" "n=8/4=2`
Promotional Banner

Similar Questions

Explore conceptually related problems

If the vectors vec(a) = 2hat(i) + hat(j) + 4hat(k), vec(b) = 4hat(i) - 2hat(j) + 3hat(k) and vec(c) = 2hat(i) - 3hat(j) - lambda hat(k) are coplanar, then findvalue of lambda

If a = 2 hat(i) - hat(j) - m hat(k) and b = (4)/(7)hat(i) - (2)/(7)hat(j) + 2hat(k) are collinear, then the value of m is equal to a) -7 b) -1 c)2 d)7

If vec(A)=hat(i)+2hat(j)+3hat(k), vec(B)=-hat(i)+2hat(j)+hat(k) and vec(C)=3hat(i)+hat(j)," then "vec(A)+tvec(B) is perpendicular to vec(C) , if t is equal to :