Q141.If A is a 2× × ×2 matrix such that adj A=6, |A|=12, then trace (A–1) is
Correct answer: 1/2
Q142.Consider the following statements: I. If A is skew-symmetric matrix, then A2 is symmetric. II. Trace of a skew-symmetric matrix of an odd order is always zero. Which of the above statements is/are true?
Correct answer: Both I and II
Q143.The system of equations x 2y 3z 1 2x y 3z 2 x y 2z 3 + + = + + = + + = + + = + + = + + = + + = + + = + + = + + = + + = + + = has
Correct answer: no solution
EnglishDSSSB TGT (SECTION-B) 28 DEC 2014
Q144.If 2 1 4 2A 3B 3 2 5 and 5 0 3 A 2B 1 6 2 then B is equal to –
Correct answer: 8 1 2/1 10 1
EnglishDSSSB TGT (SECTION-B) 28 DEC 2014
Q145.If 1 3 A 2 K and 2 A 4A 10 A, then K is equal to –
Correct answer: 4 and not 1
EnglishDSSSB TGT (SECTION-B) 28 DEC 2014
Q146.If 1 2 x 2x 3 0, 3 0 8 value of x is–
Correct answer: 23/2
EnglishDSSSB TGT (SECTION-B) 28 DEC 2014
Q147.The matrix 1 2 4 3 0 6 1 1 P has one eigen value equal to 3. The sum of the other two eigen values is–
Correct answer: p – 2
EnglishDSSSB TGT & PGT (SECTION-B) 28 DEC 2014
Q148.If A is skew symmetric matrix, then A2 is a–
Correct answer: Symmertric
EnglishSECTION B TGT & PGT TIER-I 31.11.2014
Q149.If A and B are matrices of same order, then (ABt –BAt) is a–
Correct answer: skew symmetric matrix
EnglishSECTION B PGT TIER-I 31.11.2014
Q150.If A and B are square matrices of the same order, then (A+B) (A–B) is–
Correct answer: A2 – B2 + BA – AB
EnglishSECTION B PGT TIER-I 31.11.2014
Q151.If matrix ij 3 3 A a where ij 1 if i j a 0 if i j then A2 is equal to –
Correct answer: None of these
EnglishSECTION B PGT TIER-I 31.11.2014
Q152.If A and B are invertible matrices, then which of the following is not correct?
Correct answer: 1 1 1/(A B) B A
EnglishSECTION B PGT TIER-I 31.11.2014
Q153.If A, B and C are angles of a triangle, then the determinant 1 cosC cosB cosC 1 cos A cosB cos A 1 is equal to–
Correct answer: 0
EnglishSECTION B PGT TIER-I 31.11.2014
Q154.If A is a square matrix such that 2 A, then 3 3 (A) (A) 7A is–
Correct answer: A
EnglishSECTION B PGT TIER-I 31.11.2014
Q155.The rank of a matrix 1 2 3 2 4 7 3 6 10 is–
Correct answer: 2
EnglishSECTION B PGT TIER-I 31.11.2014
Q156.The dimension of the vector space of all 3× × ×3 real matrices is–
Correct answer: 9
EnglishJDD-75-PGT TIER II-X-15 28.06.2015
Q157.Let U be a 3×3 complex Hermitian matrix which is unitary. Then the distinct eigen values of U are–
Correct answer: ± 1
EnglishJDD-75-PGT TIER II-X-15 28.06.2015
Q158.The eigen values of 3×3 real matrix P are 1, –2, 3. Then–
Correct answer: 1 2 1 P (5 2P P) 6
EnglishJDD-75-PGT TIER II-X-15 28.06.2015
Q159.Eigen values of a real symmetric matrix are always–
Correct answer: real
EnglishJDD-75-PGT TIER II-X-15 28.06.2015
Q160.If scalar λ is a characteristic root of the matrix A then the matrix (A–λ) is–
Correct answer: Singular