If the lines represented by the pair of linear equations $a_1x + b_1y + c_1 = 0$ and $a_2x + b_2y + c_2 = 0$ are coincident, then the correct relation among the following is
Two lines are coincident if they have infinitely many solutions, which occurs when their coefficients are in the same proportion: $\frac{a_1}{a_2} = \frac{b_1}{b_2} = \frac{c_1}{c_2}$. Option (c) represents parallel lines, (d) represents intersecting lines, and (b) is not a standard condition.
Q2mcq1 mark
The coordinates of the point βPβ which divides the line segment joining the points $A(x_1, y_1)$ and $B(x_2, y_2)$ internally in the ratio $1:1$ is,
The section formula for a point dividing the line in ratio $m:n$ is $\left(\frac{mx_2+nx_1}{m+n}, \frac{my_2+ny_1}{m+n}\right)$. For a midpoint ($1:1$), this simplifies to $\left(\frac{x_1+x_2}{2}, \frac{y_1+y_2}{2}\right)$.
Q3mcq1 mark
If $\sin \theta = \frac{5}{13}$, then the value of $\text{cosec } \theta$ is,
a.
$\frac{13}{12}$
b.
$\frac{5}{12}$
c.
$\frac{13}{5}$
Correct Answer
d.
$\frac{12}{13}$
Step-by-Step AI Explanation
Verified Method
By definition, $\text{cosec } \theta$ is the reciprocal of $\sin \theta$. Since $\sin \theta = \frac{5}{13}$, then $\text{cosec } \theta = \frac{1}{\sin \theta} = \frac{13}{5}$.
Q4mcq1 mark
The surface area of a sphere of radius $7\text{ cm}$ is
a.
$77\text{ cm}^2$
b.
$154\text{ cm}^2$
c.
$308\text{ cm}^2$
d.
$616\text{ cm}^2$
Correct Answer
Step-by-Step AI Explanation
Verified Method
The surface area of a sphere is $A = 4\pi r^2$. Substituting $r = 7\text{ cm}$ and $\pi \approx \frac{22}{7}$: $A = 4 \times \frac{22}{7} \times 7^2 = 4 \times 22 \times 7 = 616\text{ cm}^2$.
Q5mcq1 mark
If the $n^{\text{th}}$ term of an arithmetic progression $a_n = 3n - 2$, then its $9^{\text{th}}$ term is
a.
$-5$
b.
$25$
Correct Answer
c.
$5$
d.
$-25$
Step-by-Step AI Explanation
Verified Method
Given $a_n = 3n - 2$. For the $9^{\text{th}}$ term, substitute $n = 9$: $a_9 = 3(9) - 2 = 27 - 2 = 25$.
Q6mcq1 mark
Which of the following can be the probability of an event?
a.
$\frac{3}{2}$
b.
$-1.5$
c.
$105\%$
d.
$0.7$
Correct Answer
Step-by-Step AI Explanation
Verified Method
The probability of an event must lie between $0$ and $1$ (inclusive). Option (a) $>1$, (b) is negative, and (c) $=1.05 > 1$. Thus, only $0.7$ is a valid probability.
Q7mcq1 mark
In the figure, the value of βxβ is
a.
$60\text{ cm}$
Correct Answer
b.
$25\text{ cm}$
c.
$64\text{ cm}$
d.
$53\text{ cm}$
Step-by-Step AI Explanation
Verified Method
Since $CD \parallel AB$, $\triangle ODC \sim \triangle OAB$ by AA similarity. Therefore, the ratio of corresponding sides is equal: $\frac{AB}{CD} = \frac{OA}{OD}$. Thus, $\frac{x}{24} = \frac{40}{15}$. Simplifying $\frac{40}{15} = \frac{8}{3}$. So, $x = 24 \times \frac{8}{3} = 8 \times 8 = 64\text{ cm}$. Wait, checking calculation: $\frac{x}{24} = \frac{40}{15} \implies x = 24 \times \frac{8}{3} = 64$. However, looking at the choices, $64$ is (C). Let me re-read: $\frac{x}{24} = \frac{40}{15} = 2.66$. $x = 64$. The correct answer is (C).
Q8mcq1 mark
If the sum of the zeroes of the polynomial $P(x) = kx^2 + 2x + 3k$ is equal to the product of its zeroes, then the value of βkβ is
a.
$\frac{2}{3}$
b.
$\frac{3}{4}$
c.
$-\frac{2}{3}$
d.
$-\frac{3}{4}$
Correct Answer
Step-by-Step AI Explanation
Verified Method
For $ax^2+bx+c$, sum of zeros $= -b/a = -2/k$ and product of zeros $= c/a = 3k/k = 3$. Setting them equal: $-2/k = 3 \implies 3k = -2 \implies k = -2/3$. Wait, checking the product term: $c=3k$, $a=k$, product is $3k/k=3$. $-2/k = 3 o k = -2/3$. Looking at the provided options, if the polynomial was $kx^2+2x+3k$, product is $3k/k=3$. If the question meant $P(x)=kx^2+2x+3$, product would be $3/k$. $-2/k = 3/k o -2=3$ (impossible). Re-evaluating: sum of zeros $\alpha+\beta = -2/k$. Product $\alpha\beta = 3k/k = 3$. $-2/k = 3 \to k = -2/3$. None of the options match $-2/3$. If the polynomial was $kx^2+2x+3$, sum $-2/k$, product $3/k$, $-2/k=3/k$ is impossible. If the equation was $3x^2+2x+k$, sum $-2/3$, product $k/3$. $-2/3 = k/3 \to k=-2$. Checking math again: Sum of zeros is $-b/a = -2/k$. Product is $c/a = 3k/k = 3$. Set $-2/k = 3 \Rightarrow k = -2/3$. Option C is -2/3.
Q9short answer1 mark
Write the degree of a cubic polynomial.
Step-by-Step AI Explanation
Verified Method
The degree of a cubic polynomial is 3.
Q10short answer1 mark
How many solutions does the pair of linear equations in two variables have if they are inconsistent ?
Step-by-Step AI Explanation
Verified Method
A pair of linear equations that are inconsistent has zero (no) solutions.
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The LCM and HCF of the numbers $2^m \times 3^2$, $3^n \times 2^2$ and $3^3 \times 2^3$ are $2^4 \times 3^3$ and $2^x \times 3^y$ respectively. Find the values of $m, n, x$ and $y$.
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A person observes the top of a pole standing vertically on a level ground from the point βCβ on the same ground. Then the angle of elevation is found to be 45Β° as shown in the figure. The person moves a distance of $(\sqrt{3}-1)$ times the length of $BC$ (in metres) from the point βCβ and reaches the point βDβ on the same ground. If $AD = 12$ m, then find the angle of elevation ($\theta$) from the point βDβ to the top of the pole, the height of the pole and the distance between the foot of the pole and the point D.
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Prove that βIf in two triangles, corresponding angles are equal, then their corresponding sides are in the same ratio ( or proportion ) and hence the two triangles are similarβ.
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Prove that βIf one angle of a triangle is equal to one angle of the other triangle and the sides including these angles are proportional, then the two triangles are similarβ.
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A toy is made by attaching a hemisphere to one side and a cone on the other side of a cylinder as shown in the figure. The diameter of these three solids is same. The diameter of cylinder is 10 cm and its height is 20 cm. If the slant height of the cone is 13 cm, then find the total surface area and volume of the toy.
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From a solid cylinder of base radius 6 cm and height 27 cm, a hemisphere and a cone of radius same as that of the cylinder are carved out from the bases of the cylinder as shown in the figure. If the height of the cone is 8 cm then find the total surface area and volume of the remaining solid.
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