Q341.The trace A, where 2 -1 3 A = 3 4 5 is: 4 5 6
Correct answer: 12
Q342.If 2 1 0 0 A = 0 1 0, then A is: a b -1
Correct answer: Unit matrix
Q343.Let 3× × ×3 real matrix A be of rank 2 and 1 1 0 B = 0 1 0 Then the rank of A.B: 1 0 1
Correct answer: is equal to 2
Q344.For two similar matrices A and B the incorrect statement is
Correct answer: tr(A)=tr(B)
Q345.The value of the determinant a a - c a - b b a + c b - a is: c c - a a + b
Correct answer: 4abc
Q346.If A is a square matrix of order n and A = ∆, then the value of -5A is equal to:
Correct answer: –(5)n/∆
Q347.The value of the determinant x + y z 1 y + z x 1 z + x y 1 is
Correct answer: 0
Q348.If the determinant of an n-square matrix A is 3 and determinant of Adjoint of A is 243, then n is equal to
Correct answer: 6
Q349.The value of the determinant log6 log8 log10 log9 log12 log15 log12 log16 log20 is
Correct answer: 0
Q350.If cos sin A sin cos which one of the following is not true
Correct answer: 1 A A − α =
Q351.The inverse matrix of the matrix A exists if A is a square matrix and
Correct answer: det A ≠ 0
Q352.Let a square matrix A be such that A, A2, A3 are non-zero matrix but A4 is zero matrix. Then (I – A)–1 is
Correct answer: 2 3 I A A A + + +
Q353.The rank of the matrix 1 2 4 2 4 7 3 6 10 is:
Correct answer: 2
Q354.If 1 2 3 A 1 3 4 1 4 3 then AdjA is equal to:
Correct answer: 4
Q355.The system of equations 3x y x 1, 2x y z 2, x 2y z 1 − + λ = + + = + − λ = − − + λ = + + = + − λ = − − + λ = + + = + − λ = − − + λ = + + = + − λ = − Has unique solution if
Correct answer: 7/2
Q356.If A and B are square matrices of the same order, which of the following is true
Correct answer: (A B).(A B) (A B).(A B) + − + − + 2 2 2A 2B = −
Q357.If 1 3 2 2 5 4 2 1 − λ is a singular matrix, then value of λ is–
Correct answer: –8
Q358.If A= 2 1 1 2 − and, A2 –4A–αI then value of α is
Correct answer: -3
Q359.If 2 3 5 2 then 19A–1 is -
Correct answer: A
EnglishUP PCS (Pre) 2004 & 2007
Q360.If A and B are square matrices of order 3 such that det A = -1 and det B = 3, then det (3AB) is equal to –
Correct answer: –81