Q.1 Which of the following are the roots of the quadratic equation x² – 9x + 20 = 0?
(a) 3, 4 (b) 4, 5 (c) 5, 6 (d) 6, 7
Q.2 Which of the following equations has 2 as a root?
(a) x² – 4x + 5 = 0 (b) x² + 3x – 12 = 0 (c) 2x² – 7x + 6 = 0 (d) 3x² – 6x – 2 = 0
Q.3 Which of the following is not a quadratic equation?
(a) (x + 2)² – 2(x + 3) (b) x² + 3x – (–1)(x – 3x)² (c) (x + 2)(x – 1) = –2x – 3 (d) x² – x² + 2x + 1 = (x + 1)³
Q.4 Which of the following is a quadratic equation?
(a) x² + 2x + 1 = (4 – x)² + 3 (b) –2x² – (5 – x)(x – 2/3) (c) (k + 1)x² + 3/x² = 7, where k = –1 (d) x² – x³ – (x – 1)³
Q.5 If x = 3 is one of the roots of the quadratic equation x² – 2kx – 6 = 0, then the value of k is
(a) 1/2 (b) 3/2 (c) 3 (d) 2
Q.6 If the quadratic equation x² + 4x + k = 0 has real and equal roots, then
(a) k > 4 (b) k > 2 (c) k = 4 (d) k = 2
Q.7 Find the value(s) of k for which the quadratic equation x² + (2√2)x + 18 = 0 has equal roots
(a) 3, –3 (b) 9 (c) 9, –9 (d) √18, –√18
Q.8 Which of the following equations has no real roots?
(a) x² + 3x + 3√2 = 0 (b) 4x² – 3√2x = 0 (c) x² – 3√2 = 0 (d) 3x² + 4x + 4 = 0
Q.9 The nature of roots of the quadratic equation 2x² – 2x = 0 is:
(a) No real roots (b) 2 equal real roots (c) 2 distinct real roots (d) More than 2 real roots
Q.10 Value(s) of k for which the quadratic equation 2x² – kx + 0 has equal roots is:
(a) 0 only (b) 4 only (c) 8 only (d) 0, 8
Answer keys:
Q.1 b, Q.2 c, Q.3 c, Q.4 d , Q.5 b, Q.6 c, Q.7 a, Q.8 a , Q.9 c , Q.10 d