Geometry Questions

Multiple choice
  1. $3\sqrt { 6 } $
  2. $2\sqrt { 3 } $
  3. $6\sqrt { 3 } $
  4. none of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The distance d from the center (0,0) to the line 3x+4y-15=0 is |3(0)+4(0)-15| / sqrt(3^2+4^2) = 15/5 = 3. The radius r is 6. The chord length is 2 * sqrt(r^2 - d^2) = 2 * sqrt(36 - 9) = 2 * sqrt(27) = 2 * 3 * sqrt(3) = 6 * sqrt(3).

Multiple choice
  1. $\displaystyle \frac{10 \sqrt{5}}{2} cm$
  2. $\displaystyle \frac{5 \sqrt{5}}{4} cm$
  3. $\displaystyle \frac{5 \sqrt{5}}{2} cm$
  4. $\displaystyle \frac{5 \sqrt{10}}{2} cm$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Let r be the radius. Distance from center to chord PQ (length 11) is sqrt(r^2 - 5.5^2). Distance to chord MN (length 5) is sqrt(r^2 - 2.5^2). Since they are on opposite sides, the sum of distances is 6. Solving sqrt(r^2 - 30.25) + sqrt(r^2 - 6.25) = 6 leads to r = 5*sqrt(5)/2.

Multiple choice
  1. ${ x }^{ 2 }+{ y }^{ 2 }-4x+2=0$
  2. ${ x }^{ 2 }+{ y }^{ 2 }-4x+1=0$
  3. ${ x }^{ 2 }+{ y }^{ 2 }-8x+8=0$
  4. ${ x }^{ 2 }+{ y }^{ 2 }-4y+2=0$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Circle center (h, 0), radius r. Touches y=x (x-y=0), so distance from (h,0) to x-y=0 is r: |h-0|/sqrt(2) = r, so h^2 = 2r^2. Chord length 2 on y - x/sqrt(3) = 0. Distance from center to line is sqrt(r^2 - 1^2). Solving leads to x^2 + y^2 - 4x + 2 = 0.

Multiple choice
  1. $128$
  2. $128\sqrt3$
  3. $256$
  4. $512$
  5. $512\sqrt3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A rhombus formed by two radii and two chords in a circle of radius R must have sides of length R. Since the radii form an angle at the center, the rhombus is composed of two equilateral triangles with side 16. Area = 2 * (sqrt(3)/4 * 16^2) = 128 * sqrt(3).

Multiple choice
  1. $\left( { a }_{ 1 }^{ 2 }+{ a }_{ 2 }^{ 2 } \right) +\left( { b }_{ 1 }^{ 2 }+{ b }_{ 2 }^{ 2 } \right) ={ r }_{ 1 }^{ 2 }+{ r }_{ 2 }^{ 2 }$
  2. $\left( { a }_{ 1 }^{ 2 }-{ a }_{ 2 }^{ 2 } \right) +\left( { b }_{ 1 }^{ 2 }-{ b }_{ 2 }^{ 2 } \right) ={ r }_{ 1 }^{ 2 }-{ r }_{ 2 }^{ 2 }$
  3. ${ \left( { a }_{ 1 }^{ 2 }-{ b }_{ 2 } \right) }^{ 2 }+\left( { a }_{ 2 }^{ 2 }+{ b }_{ 2 }^{ 2 } \right) ={ r }_{ 1 }^{ 2 }+{ r }_{ 2 }^{ 2 }$
  4. $\left( { a }_{ 1 }^{ 2 }-{ b }_{ 1 }^{ 2 } \right) +\left( { a }_{ 1 }^{ 2 }+{ b }_{ 2 }^{ 2 } \right) ={ r }_{ 1 }^{ 2 }+{ r }_{ 2 }^{ 2 }$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

For two circles touching externally, the distance between centers equals the sum of radii: (a1-a2)^2 + (b1-b2)^2 = (r1+r2)^2. The tangent at the common point passes through the origin. This geometric condition leads to the relation (a1^2 - a2^2) + (b1^2 - b2^2) = r1^2 - r2^2.

Multiple choice
  1. $ false,\quad since\quad the\quad radius\quad of\quad { C }_{ 1 }\neq the\quad radius\quad of{ \quad C }_{ 2 }.\quad \\ $
  2. $ True,\quad since\quad the\quad radius\quad of\quad { C }_{ 1 }=2\times (the\quad radius\quad of{ \quad C }_{ 2 }).\quad \quad \\ $
  3. $ False,\quad \quad since\quad \theta _{ 1 }\neq \theta _{ 2 }.\\ $
  4. $ True,\quad since\quad \theta _{ 1 }=\theta _{ 2 }.\\ $
Reveal answer Fill a bubble to check yourself
B Correct answer
Multiple choice
  1. Statement - 1 is true, statement -2 is true and statement -2 is correct explanation for statement -1.

  2. Statement - 1 is true, statement -2 is true and statement -2 is NOT the correct explanation for statement -1.

  3. Statement - 1 is true, statement -2 is false

  4. Statement - 1 is false , statement -2 is true

Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice
  1. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is a correct explanation for STATEMENT-1

  2. STATEMENT-1 is True, STATEMENT-2 is True; STATEMENT-2 is NOT a correct explanation for STATEMENT-1

  3. STATEMENT-1 is True, STATEMENT-2 is False

  4. STATEMENT-1 is False, STATEMENT-2 is True

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 2 is a known theorem: the locus of the midpoint of a chord subtending angle theta at the center is a circle of radius r*cos(theta/2). For theta=pi/2, radius = r*cos(pi/4) = r/sqrt(2). Here r=2, so radius = 2/sqrt(2) = sqrt(2). The locus is x^2 + y^2 = 2. Statement 1 claims x^2 + y^2 = 1, which is false.

Multiple choice
  1. $(\mathrm{a}^{2}+\mathrm{b}^{2})(\mathrm{x}^{2}+\mathrm{y}^{2})=2\mathrm{a}\mathrm{b}(\mathrm{b}\mathrm{x}+\mathrm{a}\mathrm{y})$
  2. $(\mathrm{a}^{2}+\mathrm{b}^{2})(\mathrm{x}^{2}+\mathrm{y}^{2})=2\mathrm{a}\mathrm{b}(\mathrm{a}\mathrm{x}+\mathrm{b}\mathrm{y})$
  3. $\mathrm{x}^{2}+\mathrm{y}^{2}=\dfrac {2\mathrm{a}\mathrm{b}}{(\mathrm{a}^{2}+\mathrm{b}^{2}) (ax-by)}$
  4. $\mathrm{x}^{2}+\mathrm{y}^{2}= \dfrac {ab}{(\mathrm{a}^{2}+\mathrm{b}^{2})(\mathrm{a}\mathrm{x}+\mathrm{b}\mathrm{y})}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The common chord of the two circles is found by subtracting the equations, resulting in ax + by = 0. The equation of a circle passing through the intersection of two circles is S1 + k(S2-S1) = 0, or more simply, the family of circles passing through the intersection. Using the condition that the common chord is a diameter, we derive the correct equation.

Multiple choice
  1. (i) circumference. (ii) the circle. (iii) major arc. (iv) two radii and the corresponding arc. (v) a chord and the corresponding arc. (vi) one and only one point. (vii) is one and only one. (viii) two.

  2. (i) circumference.(ii) the circle.(iii)  major segment.(iv) two radii and the corresponding arc.(v) a chord and the corresponding arc. (vi) one and only one point.(vii) is two and only two.(viii) one. 

  3.  (i) circumference. (ii) the diameter. (iii) major arc.(iv) two radii and the corresponding semicircle.(v) a diameter and the corresponding arc.(vi) two and only two point.(vii) is two and only two.(viii)\quad two. 

  4.  (i) circumference. (ii) the circle.(iii) major arc.(iv) two radii and the corresponding chord.(v) a chord and the corresponding diameter.(vi) two and only two point.(vii) is two and only  two.(viii) two. 

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The definitions provided in option A are geometrically accurate: an arc is part of a circumference, diameter bisects a circle, sector is bounded by two radii and an arc, and tangents from an external point are two.

Multiple choice
  1. $a:n^{2}R^{2}\sin^{2}\cfrac{\pi}{n},b:\cfrac{2}{B_{1}}$
  2. $a:n^{2}R^{4}\sin^{2}\cfrac{\pi}{n},b:\cfrac{2}{B_{2}}$
  3. $a:n^{2}R^{2}\sin^{2}\cfrac{\pi}{n},b:\cfrac{1}{B_{1}}$
  4. $a:n^{2}R^{4}\sin^{2}\cfrac{\pi}{n},b:\cfrac{1}{B_{2}}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

This is a standard geometric property of inscribed and circumscribed polygons. For part (a), A1B1 = n^2 * R^4 * sin^2(pi/n). For part (b), the harmonic mean relation leads to 2/B2 = 1/A2 + 1/B1, which rearranges to the required form.

Multiple choice
  1. STATEMENT 1 is True, STATEMENT 2 is True; STATEMENT 2 is a correct explanation for STATEMENT 1.

  2. STATEMENT 1 is True, STATEMENT 2 is True; STATEMENT 2 is NOT a correct explanation for STATEMENT 1.

  3. STATEMENT 1 is True, STATEMENT 2 is False.

  4. STATEMENT 1 is False, STATEMENT 2 is True.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The circle C has center (-3, 5) and radius sqrt(9 + 25 - 30) = 2. A line 2x + 3y + k = 0 is a diameter if it passes through (-3, 5), meaning 2(-3) + 3(5) + k = 0, so k = -9. For L1, p-3 = -9 implies p = -6. For L2, p+3 = -9 implies p = -12. Since p can vary, L1 being a chord does not force L2 to be a diameter, making Statement 1 true. Statement 2 is false because if L1 is a diameter, L2 is just another line with a different constant term, which could also be a chord or diameter depending on p.

Multiple choice
  1. $\dfrac { { x }^{ 2 } }{ { a }^{ 2 } } +\dfrac { { y }^{ 2 } }{ { b }^{ 2 } } =\dfrac { 1 }{ { c }^{ 2 } } $
  2. $\dfrac { { x }^{ 2 } }{ { a }^{ 2 } } +\dfrac { { y }^{ 2 } }{ { b }^{ 2 } } =\dfrac { 1 }{ { c }^{ 4 } } $
  3. $\dfrac { { x }^{ 2 } }{ { a }^{ 4 } } +\dfrac { { y }^{ 2 } }{ { b }^{ 4 } } =\dfrac { 1 }{ { c }^{ 2 } } $
  4. none of these

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The chord of contact of tangents from (alpha, beta) to the ellipse x^2/a^2 + y^2/b^2 = 1 is (alpha*x)/a^2 + (beta*y)/b^2 = 1. If this line touches the circle x^2 + y^2 = c^2, the perpendicular distance from the origin to the line must equal the radius c. Thus, 1 / sqrt(alpha^2/a^4 + beta^2/b^4) = c, leading to alpha^2/a^4 + beta^2/b^4 = 1/c^2.

Multiple choice
  1. P -1, Q -2, R - 3, S - 4

  2. P -4, Q - 3, R - 2, S - 1

  3. P -3, Q - 1, R - 2, S - 4

  4. P - 4, Q - 1, R - 2, S - 3

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This is a standard calculus/geometry problem involving optimization of areas. P corresponds to the maximum area of the triangle (4), Q to the rectangle (1), R to the distance (2), and S to the bounded area (3).