Quadratic Equations
Practice Questions
MCQ (Single Correct Answer)
1

If one root of the equation $${x^2} + (1 - 3i)x - 2(1 + i) = 0$$ is $$-$$1 + i, then the other root is

WB JEE 2008
2

The equation $${x^2} - 3|x| + 2 = 0$$ has

WB JEE 2008
3

If $$\alpha$$, $$\beta$$ be the roots of $${x^2} - a(x - 1) + b = 0$$, then the value of $${1 \over {{\alpha ^2} - a\alpha }} + {1 \over {{\beta ^2} - a\beta }} + {2 \over {a + b}}$$ is

WB JEE 2009
4

The sum of all real roots of the equation $$|x - 2{|^2} + |x - 2| - 2 = 0$$ is

WB JEE 2009
5

The quadratic equation whose roots are three times the roots of $$3a{x^2} + 3bx + c = 0$$ is

WB JEE 2009
6

If a, b, c are real, then both the roots of the equation $$(x - b)(x - c) + (x - c)(x - a) + (x - a)(x - b) = 0$$ are always

WB JEE 2009
7

If $$\alpha$$, $$\beta$$ be the roots of the quadratic equation x2 + x + 1 = 0 then the equation whose roots are $$\alpha$$19, $$\beta$$7 is

WB JEE 2010
8

The roots of the quadratic equation $${x^2} - 2\sqrt 3 x - 22 = 0$$ are

WB JEE 2010
9

The quadratic equation $${x^2} + 15|x| + 14 = 0$$ has

WB JEE 2010
10

If sin $$\theta$$ and cos $$\theta$$ are the roots of equation ax2 $$-$$ bx + c = 0, then a, b and c satisfy the relation

WB JEE 2011
11

Let a, b, c be three real numbers such that a + 2b + 4c = 0. Then the equation ax2 + bx + c = 0

WB JEE 2011
12

If the ratio of the roots of the equation $$p{x^2} + qx + r = 0$$ is $$a:b$$, then $${{ab} \over {{{(a + b)}^2}}}$$ =

WB JEE 2011
13

If $$\alpha$$ and $$\beta$$ are the roots of the equation x2 + x + 1 = 0, then the equation whose roots ar $$\alpha$$19 and $$\beta$$7 is

WB JEE 2011
14
The quadratic equation 2x2 $$-$$ (a3 + 8a $$-$$ 1)x + a2 $$-$$ 4a = 0 possesses roots of opposite sign. Then,
WB JEE 2012
15
For what value of ' $a$ ', the sum of the squares of the roots of the equation $x^2-(a-2) x-a+1=0$ will have the least value?
WB JEE 2025
16

If the sum of the squares of the roots of the equation $x^2-(a-2) x-(a+1)=0$ is least for an appropriate value of the variable parameter $a$, then that value of ' $a$ ' will be

WB JEE 2025
17

If $$\mathrm{P}(x)=\mathrm{a} x^2+\mathrm{b} x+\mathrm{c}$$ and $$\mathrm{Q}(x)=-\mathrm{a} x^2+\mathrm{d} x+\mathrm{c}$$ where $$\mathrm{ac} \neq 0$$, then $$\mathrm{P}(x) \cdot \mathrm{Q}(x)=0$$ has (a, b, c, d are real)

WB JEE 2024
18

Let $$\mathrm{N}$$ be the number of quadratic equations with coefficients from $$\{0,1,2, \ldots, 9\}$$ such that 0 is a solution of each equation. Then the value of $$\mathrm{N}$$ is

WB JEE 2024
19

If $$a, b, c$$ are distinct odd natural numbers, then the number of rational roots of the equation $$a x^2+b x+c=0$$

WB JEE 2024
20

If one root of $${x^2} + px - {q^2} = 0,p$$ and $$q$$ are real, be less than 2 and other be greater than 2, then

WB JEE 2023
21

If a, b are odd integers, then the roots of the equation $$2a{x^2} + (2a + b)x + b = 0$$, $$a \ne 0$$ are

WB JEE 2022
22

The value of a for which the sum of the squares of the roots of the equation $${x^2} - (a - 2)x - a - 1 = 0$$ assumes the least value is

WB JEE 2022
23
Let $$\alpha$$, $$\beta$$ be the roots of the equation x2 $$-$$ 6x $$-$$ 2 = 0 with $$\alpha$$ > $$\beta$$. If an = $$\alpha$$n $$-$$ $$\beta$$n for n $$\ge$$ 1, then the value of $${{{a_{10}} - 2{a_8}} \over {2{a_9}}}$$ is
WB JEE 2021
24
The expression ax2 + bx + c (a, b and c are real) has the same sign as that of a for all x if
WB JEE 2020
25
Let z1 and z2 be two imaginary roots of z2 + pz + q = 0, where p and q are real. The points z1, z2 and origin form an equilateral triangle if
WB JEE 2020
26
If P(x) = ax2 + bx + c and Q(x) = $$ - $$ax2 + dx + c, where ac $$ \ne $$ 0 [a, b, c, d are all real], then P(x).Q(x) = 0 has
WB JEE 2020
27
Let a, b, c be real numbers such that a + b + c < 0 and the quadratic equation ax2 + bx + c = 0 has imaginary roots. Then,
WB JEE 2019
28
If $${b_1}{b_2} = 2({c_1} + {c_2})$$ and b1, b2, c1, c2 are all real numbers, then at least one of the equations $${x^2} + {b_1}x + {c_1} = 0$$ and $${x^2} + {b_2}x + {c_2} = 0$$ has
WB JEE 2018
29
The greatest integer which divides $$(p + 1)(p + 2)(p + 3)...(p + q)$$ for all $$p \in N$$ and fixed $$q \in N$$ is
WB JEE 2017
30
If p, q are odd integers, then the roots of the equation $$2p{x^2} + (2p + q)x + q = 0$$ are
WB JEE 2017
31
Let $$\alpha$$ and $$\beta$$ be the roots of $${x^2} + x + 1 = 0$$. If n be a positive integer, then $$\alpha$$n + $$\beta$$n is
WB JEE 2017
32
For real x, the greatest value of $${{{x^2} + 2x + 4} \over {2{x^2} + 4x + 9}}$$ is
WB JEE 2017
33
If p, q are the roots of the equation x2 + px + q = 0, then
WB JEE 2016
34
The number of values of k, for which the equation x2 $$-$$ 3x + k = 0 has two distinct roots lying in the interval (0, 1), are
WB JEE 2016
35
If $$\alpha$$ and $$\beta$$ are roots of ax2 + bx + c = 0, then the equation whose roots are $$\alpha$$2 and $$\beta$$2, is
WB JEE 2016