Question

A vector is represented as 4î + 3ĵ. What is its magnitude?

(a) 5

(b) 10

(c) 4

(d) 3

The question was posed to me during an interview for a job.

This interesting question is from Motion in a Plane topic in chapter Motion in a Plane of Physics – Class 11

Answer 1

Correct answer is (a) 5

Easiest explanation: The magnitude of any vector can be found by taking the square root of sum of the squares of its two components. Hence, the sum of the squares of components is equal to 4^2 + 3^2 = 25. Square root of 25 = 5. Hence, the answer is 5.