Mensuration Questions

Multiple choice
  1. $\pi \mathrm{c}^{2}$
  2. $\displaystyle \frac{\pi \mathrm{c}^{2}}{4}$
  3. $\displaystyle \frac{\pi \mathrm{c}}{2}$
  4. $\displaystyle \frac{\pi}{4\mathrm{c}^{2}}$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A circle touching the y-axis (x=0) and the line x=c has a diameter of c. Thus, the radius is c/2. The center lies on the x-axis, so the center is at (c/2, 0). The area is pi * r^2 = pi * (c/2)^2 = pi * c^2 / 4.

Multiple choice
  1. 412 $\displaystyle cm^{2} $
  2. 616 $\displaystyle cm^{2} $
  3. 500 $\displaystyle cm^{2} $
  4. None of these

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

A square with area 484 has a side of 22 cm, so the perimeter (wire length) is 88 cm. A circle with circumference 88 cm has a radius r = 88 / (2 * 22/7) = 14 cm. The area of the circle is pi * r^2 = (22/7) * 14 * 14 = 616 sq cm.

Multiple choice
  1. $\displaystyle C_{1}$ will enclose maximum volume.
  2. $\displaystyle C_{2}$ will enclose maximum volume.
  3. $\displaystyle C_{3}$ will enclose maximum volume.
  4. Each of $\displaystyle C_{1},C_{2}\: \: and\: \: C_{3}$ will enclose equal volume.
Reveal answer Fill a bubble to check yourself
C Correct answer
Multiple choice
  1. $6104$ $\displaystyle cm^{2}$ Area covered by the cylinder in 1 round $= $ its curved surface area.
  2. $6804$ $\displaystyle cm^{2}$ Area covered by the cylinder in 1 round $= $ its curved surface area.
  3. $6404$ $\displaystyle cm^{2}$ Area covered by the cylinder in 1 round $= $ its curved surface area.
  4. $6204$  $\displaystyle cm^{2}$ Area covered by the cylinder in 1 round $= $ its curved surface area.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The circumference is 8 cm and length is 21 cm. In one round, the area covered is the curved surface area: 8 * 21 = 168 cm^2. The cylinder rolls for 4.5 seconds at 9 rounds per second, totaling 40.5 rounds. Total area = 40.5 * 168 = 6804 cm^2.

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
A Correct answer
Multiple choice
  1. $\displaystyle 14373\frac{1}{3}\, cm^{3}$, $3080\, cm^{2}$, Rs. $2464$
  2. $\displaystyle 1473\frac{1}{2}\, cm^{3}$, $3582\, cm^{2}$, Rs. $2499$
  3. $\displaystyle 14573\frac{1}{5}\, cm^{3}$, $3810\, cm^{2}$, Rs. $2762$
  4. $\displaystyle 14370\frac{1}{7}\, cm^{3}$, $3087\, cm^{2}$, Rs. $2465$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The cylinder height is 28 - 14 = 14 cm. Volume = (1/3)*pi*r^2*h_hemisphere + pi*r^2*h_cylinder = (2/3)*pi*14^3 + pi*14^2*14 = 14373.33 cm^3. Surface area = 2*pi*r^2 (hemisphere) + 2*pi*r*h (cylinder) = 2*pi*14^2 + 2*pi*14*14 = 3080 cm^2. Cost = 3080 * 0.80 = 2464.