Ratios Using Sectors of Circles

Q. The ratio of the radii of two circles is 3 : 2. What is the ratio of their circumference?

1. 2:3
2. 1:3
3. 3:2
4. 3:1

Q.

The given figure shows a semi - circle :

The semicircle has a circumference of 12 cm and the radius is 4 cm. Find the ratio between the circumference and the diameter if this is converted into a full circle.

1. 4 : 3

2. 2 : 1

3. 3 : 1

4. 3 : 2

Q.

The given figure shows a circle and a coloured quadrant which is cut out from the circle :

If the radius of the circle is 7 cm , then what is the ratio between the perimeter of the full circle and the perimeter of the quadrant of the circle. (Perimeter = 2$\pi$r)

1. 44 : 25

2. 44 : 18

3. 38 : 25

4. 4 : 1

Q. A steel wire bent in the form of a square of area $121c{m}^2$. If the same wire is bent in the form of a circle, then the area of the circle is

1. $130c{m}^2$
2. $136c{m}^2$
3. $154c{m}^2$
4. $168c{m}^2$

Q.

1 quadrant has been removed from the given circle :

If 8 such figures are taken and compared with 9 full circles, what would be the ratio between these figures and full circles taking them as $\frac{3}{4}$ of the full circle.

1. 3 : 9

2. 8 : 9

3. 3 : 4

4. 2 : 3

Q. In figure, AOBCA represents a quadrant of a circle of radius $3.5$cm with centre O. Calculate the area of the shaded portion (Take $\pi =\frac{22}{7}$)

1. $2.156c{m}^2$
2. $4.653c{m}^2$
3. $6.125c{m}^2$
4. None of these
   

Q.

The given figure shows a coloured region in a circle.

If the coloured part is compared with the full circle, what is the ratio of the coloured part to the full circle?

1. 1 : 3

2. 1 : 2

3. 1 : 4

4. 2 : 3

Q. In the figure, $OACB$ represents a quadrant of a circle. The radius $OA=3.5cm,OD=2cm$.
The area of the shaded portion is

1. $613$ ${cm}^2$
2. $6.13$ ${cm}^2$
3. $316$ ${cm}^2$
4. $3.16$ ${cm}^2$

Q.

1 quadrant has been removed from the given circle :

If 8 such figures are taken and compared with 9 full circles, what would be the ratio between these figures and full circles taking them as $\frac{3}{4}$ of the full circle.