# NEET Physics Mathematical Tools Questions Solved

NEET - 2016

If the magnitude of sum of two vectors is equal to the magnitude of difference of the two vectors, the angle between these vectors is
(a)90° (b)45° (c) 180° (d) 0°

Concept Videos :-

#20 | Vectors: Introduction
#22 | Vectors : Subtraction

Concept Questions :-

Resultant of Vectors

(a) Suppose two vectors are P and Q. It is given that [P+Q]=[P-Q]

Let angle between P and Q is φ.
P2+Q2+2PQ cosφ=P2+Q2-2PQcosφ
=> 4PQcosφ=0
=> cosφ=0   [P,Q≠0]
=> φ=π/2=90°

Difficulty Level:

• 64%
• 11%
• 13%
• 13%
Crack NEET with Online Course - Free Trial (Offer Valid Till September 22, 2019)