Q.

Two particles are located at equal distance from origin. The position vectors of those are represented by A=2i^+3nj^+2k^ and B=2i^2j^+4pk^, respectively. If both the vectors are at right angle to each other, the value of n1 is __________.          [2025]


Ans.

(3)

A·B=0 and |A|=|B|

 4 – 6n + 8p = 0

3n – 4p = 2          ... (i)

Also 4+9n2+4=4+4+16p2

3n=±4p          ... (ii)

±4p4p=2

Taking –ve sign

–8p = 2

p=14, 3n+1=2  n=13