Let A by any `mxxn` matrix then `A^2` can be found only when (A) `mltn` (B) `m=n` (C) `mgtn` (D) none of these

If A=[a_(ij)]_(mxxn) is a matrix of rank r then (A) rltmin{m,n} (B) rlemin{m,n} (C) r=min{m,n} (D) none of these

If A=[a_(ij)]_(mxxn) is a matrix of rank r then (A) r=min{m,n} (B) rlemin{m,n} (C) rltmin{m,n} (D) none of these

For a non singular matrix A of order n the rank of A is (A) less than n (B) equal to n (C) greater than n (D) none of these

If for a square matrix A,A^2=A then |A| is equal to (A) -3 or 3 (B) -2 or 2 (C) 0 or 1 (D) none of these

Inverse of diagonal matrix is (A) a diagonal matrix (B) symmetric (C) skew symmetric (D) none of these

If A is a square matrix of order nxxn and lamda is a scalar then |lamdaA| is (A) lamda|A| (B) lamda^n|A| (C) |lamda||A| (D) none of these

Nematodes are not found in (a) soil (b) freshwater (c) sea water (d) none of these

If A is an invertible symmetric matrix the A^-1 is A. a diagonal matrix B. symmetric C. skew symmetric D. none of these

Let n be a positive integer such that sin (pi/(2n))+cos (pi/(2n))= sqrt(n)/2 then (A) n=6 (B) n=1,2,3,….8 (C) n=5 (D) none of these

If y=m x+c touches the parabola y^2=4a(x+a), then (a) c=a/m (b) c=a m+a/m c=a+a/m (d) none of these