CLASS: M.Sc. MATHEMATICS 15N/455 ST. JOSEPH’S COLLEGE (AUTONOMOUS) TIRUCHIRAPPALLI – 620 002 SEMESTER EXAMINATIONS – NOVEMBER 2015 TIME: 40Minutes. MAXIMUM MARKS: 30 SEM SET PAPER CODE TITLE OF THE PAPER I 2015 14PMA1104 LINEAR ALGEBRA SECTION - A Answer all the questions: 30 1 = 30 Choose the correct answer: 1. 2. 3. 4. 5. 6. Any subset of a vector space which contains more than dim V vectors is _______. a) Linearly dependent b) Linearly independent c) Empty set d) The space V In a row-reduced matrix, each column which contains the leading non-zero entry of some row has all its other entries a) 1 b) 0 c) 2 d) n Identify the non-elementary matrix from the following 2x2 matrices 1 𝑐 1 0 0 1 0 𝑐 a) [ ] b) [ ] c) [ ] d) [ ] 0 1 0 𝑐 1 0 1 0 If dimW1 = 3, dimW2 = 5, dim(W1 ∩ W2) = 2 thendim(W1 + W2)= a) 8 b) 10 c) 7 d) 6 A basis for a vector space V is a set of vectors which --a) Islinearly independent and spans V b) Is linearly independent c) spans V d) Is linearly dependent and spans V If A is an p x n matrix and B is an n x p matrix, then the matrix BA is an ______ matrix. a) n x n b) m x m c) m x n d) n x m 7. 8. 9. 10. 11. 12. 13. 14. 15. If the vector space V is finite dimensional then the nullity of linear transformation T is the dimension of _______. a) Range of T b) V c) Null space of T d) Empty set If V and Ware vector spaces over the field F, a linear operator on V is a linear transformation from -----------a) V into W b) V into V c) V into F d) F into F If F is a field and if T is an operator on F2 defined by T(x1,x2) =(x1,0) and B = {e1 ,e2}is the standard basis then [𝑇]𝐵 = ________. 0 1 0 0 0 0 1 0 a) [ ] b) [ ] c) [ ] d) [ ] 0 0 1 0 0 1 0 0 In a vector space of dimension n , a subspace of dimension ______ is called a hyperspace a) n +1 b) n – 1 c) n d) 2 n If V is a finite-dimensional vector space over the field F and W is a subspace of V then dimV is _______. a) dim V0 + dim W b) dim V0 + dim W0 c) dim W - dim W0 d) dim W + dim W0 The null space of the transpose of a linear transformation T from vector space V into vector space W is the annihilator of the _____ of T. a) range of T b) transpose c) rank of T d) null space If f, g and h are polynomials over the field F such that f≠0 and fg = fh then _______. a) f = h b) f = g c) g = h d) f = g = h If f is a polynomial over the field F and c is an element of F then f is divisible by x-c if and only if a) f(c) = 1 b) f(c) = 0 c) f(c) ≠ 0 d) f(c) ≠ 1 If c is a root of the polynomial f, then the multiplicity of c as a root of f is the largest positive integer r such that ______ divides f. a) (x+c)r b) (x-c)r c) (x+c)r+1 d) (x-c)r-1 16. The polynomial f in F[x] is said to be _______ if there exists no polynomials g, h in F[x] of deg ≥ 1 such that f = gh. a) reducible b) irreducible c) prime d) monic 17. The polynomial x2 +1 is _______ over the field R of real numbers. a) irreducible b) reducible c) monic d) scalar 18. The field F is algebraically closed if every prime polynomial over F has degree _______. a) 1 b) 0 c) > 1 d) any finite positive integer 19. If V is a vector space over the field F and T is a linear operator on V then any vector α such that Tα=cα is called a _______ of T associated with the characteristic value c. a) latent root b) characteristic vector c) spectral value d) eigen value 20. If T is a linear operator on a finite-dimensional space V and c is a characteristic value of T then ________. a) det(cT-I) = 0 b) det(T-cI) = 0 c) det(T-I) = 0 d) det(T-cI) = 1 21. If A is an n×n matrix over the field F , a characteristic value of A in F is a scalar c in F such that the matrix (A-cI) is _______. a) invertible b) nonsingular c) singular d) none of these 22. If A=[0 −1]represents a linear operator T on 𝑅2 in the standard 1 0 ordered basis then the characteristic values of T are _______. a) 1 and -1 b) i and –i c) 1 and 0 .5 d) no 23. If T is a linear operator on the finite dimensional space V then T is _______ if there is a basis for V, each vector of which is a characteristic vector of T. a) diagonalizable b) T-Conductor c) triangulable d) none 24. If D is any alternating 𝑛 – Linear function on 𝐾 𝑛 𝑋 𝑛 , then for each 𝑛 𝑋 𝑛 matrix 𝐴 b) D(A) = det D(I) a) D(A) = D(I) d) None of these c) D(A) = det A 25. If W is a subspace of a vector space V and if T is a linear operator on V then W is _____ under T if for each vector α in W the vector Tα is in W . a) null space b) T-conductor c) invariant d) annihilator 26. If W is an invariant subspace for T and α be a vector in V then ---_______ of α into W is the set of all polynomials g such that g(T)α is in W. a) T-annihilate b) null space c) invariant d) T-conductor 27. If W is an invariant subspace for the linear operator T, the conductor S(α ; W) is _______ in the polynomial algebra F[x]. b) a T-conductor a) an ideal d) invariant c) a T-annihilate 28. The linear operator T is _______ if there is an ordered basis in which T is represented by a triangular matrix b) invariant a) triangulable d) annihilator c) diagonalizable 29. A projection of vector space V is a linear operator E on V such that _______. a) E=1 b) E=0 c) E2 = E d) E2 =1 30. If the minimal polynomial for a linear operator T on the finite dimensional vector space V over F decomposes over F into a product of linear polynomials then there is a diagonalizable operator D on V and a nilpotent operator N on V such that _____. b) T=D-N & DN = ND a) T=D+N & DN = ND d) T=D/N & DN = ND c) T=DN & DN = ND *****************