Area of a Circle

Q. A wheel of radius $70$ cm starts moving in such a way that point A comes from bottom to top as shown. The distance travelled by the wheel is ____ cm.

1. $220$
2. $440$
3. $100$
4. $120$

Q.

If the radius of the circle is R. Find the area of the circle.

1. 38.5 cm²

2. 42 cm²

3. 30 cm²

4. 35 cm²

Q.

Radius of a circle is doubled. What will be the ratio of areas of the new circle to the area of the given circle?

1. 4:8

2. 2:3

3. 4:1

4. 5:3

Q.

What is the area of a circle with radius r units?

1. $2\pi r^2$

2. $4\pi r^2$

3. $\pi r^2$

4. $r^2$

Q.

State true or false.
Area of a circle is inversely proportional to the radius of circle.

1. True

2. False

Q.

The area of a circle is 394.24 $c{m}^2$. Then the radius of the circle in cm is _______.

1. 11.3

2. 11.2

3. 11.1

4. 11.4

Q.

If the radius of a circle is $\frac{7}{\sqrt{\pi }}$ cm, then find the area of the circle (in square cm).

1. $\frac{49}{\pi }$

2. 49

3. 22

4. 154

Q.

Find the diameter of a circle in cm whose area is equal to the sum of the area of the two circles of radii 24 cm and 7 cm.

1. 25

2. 62

3. 50

4. 31

Q.

State true or false.
If the radius of a circle is $\frac{7}{\sqrt{\pi }}$ cm, then the area of the circle in $c{m}^2$ is $\frac{49}{{\pi }^2}$.

1. False

2. True

Q.

In a grass field, a bull is tied to a pole with a rope of length 7 meters. How much area of field is it allowed to be grazed?
$(Take\pi =\frac{22}{7}$)

1. 110 $m^2$

2. 55 $m^2$

3. 100 $m^2$

4. 154 $m^2$