If A is a skew-symmetric matrix of order n, then

The correct answer is Option (2) → \(a_{ij}=0\), where i = j

A matrix is skew-symmetric when \(A' = -A\), that is,

    \(a_{ji} = -a_{ij}\) for all i and j

For a diagonal element put j = i:

    \(a_{ii} = -a_{ii}\)
    \(2a_{ii} = 0\)
    \(a_{ii} = 0\)

So every diagonal element of a skew-symmetric matrix is zero: \(a_{ij} = 0\) where i = j.

NCERT (2026-27 edition):
Symmetric and Skew Symmetric Matrices