Circumference

Q.

The perimeter of a semicircle of radius $7cm$ is equal to

1. $32cm$
2. $22cm$
3. $44cm$
4. $48cm$

Q.

Circumference of a circle with radius $r$ and diameter $d$ is ____.

1. $\pi r$

2. $\pi r^2$

3. $\pi d$

4. $\pi d^2$

Q.

How many revolution would a cycle wheel of diameter 1.6m make to cover a distance of 352metres

Q.

To determine the diameter of a rod a student wound a thread $5\mathrm{times}$ around the rod and measured the length of thread as $156\mathrm{mm}$on a meter scale. Using this value he calculated the diameter of the rod. If the actual diameter of the rod is $9.94\mathrm{mm}$what is the error that could result in the method followed by the student?$\mathrm{Take}\mathrm{\pi }=\frac{22}{7}$

1. $+0.01\mathrm{mm}$

2. $-0.01\mathrm{mm}$

3. $+0.02\mathrm{mm}$

4. $-0.02\mathrm{mm}$

Q. Question 8
A small village, having a population of 5000, required 75 L of water per head per day. The village has got an overhead tank of measurement $40m\times 25m\times 15m$. for how many days will the water of this last?

Q. A car has a tyre of diameter 28 cm.What is the distance covered by the car if the tyre rotates 150 times?

1. 124 m
2. 132 m
3. 136 m
4. 142 m

Q.

The ratio of the circumference of a circle to its ____ is $\pi$.

1. area

2. diameter

3. $radiu{s}^2$

4. radius

Q. The cost of fencing a circular park is ₹2200 at the rate of ₹70 per metre. What is the radius of the circular park ?

1. 7 m
2. 9 m
3. 10 m
4. 5 m

Q. What is the circumference of a circle that has a radius of 7 cm?

1. 22 cm
2. 44 cm
3. 88 cm
4. 176 cm

Q. If the radius of a circle is increased by 3%, calculate the percentage increase in the area of the circle? (round off to 2 decimal places)

1. 10.25%
2. 6.09%
3. 8.16%
4. 4.04%

Q. The rectangular shape of the wire 14 cm long and 8 cm broad is bent to the form of a circle. Find the diameter of the circle.

1. 7 cm
2. 12 cm
3. 14 cm
4. 21 cm

Q. The circumferences of two circles are in the ratio $5:7$, find the ratio between their radii.

1. $\frac{5}{7}$
2. $\frac{5}{6}$
3. $\frac{2}{5}$
4. $\frac{3}{5}$

Q.

Find the circumference of the circle from the figure.
(Take $\pi$ as $\frac{22}{7}$)

1. 8 cm

2. 88 cm

3. 120 cm

4. 132 cm

Q. Saima wants to put a lace on the edge of a circular table cover of diameter 1.5 m. Find the length of the lace required and also find its cost if one meter of the lace costs ₹ 15 $(Take\pi =3.14)$

Q.

A car has to travel 0.121 km to reach from A to B. If the radius of the tyre is 7 cm. How many times will the tyre rotate while the car travels from A to B ? (Use π = $\frac{22}{7}$)

1. 275

2. 250
3. 300
4. 325

Q. Saima wants to put a lace on the edge of a circular table cover of diameter 1.5 m. Find the length of the lace required and also find its cost if one meter of the lace costs ₹ 15 $(Take\pi =3.14)$

Q. The floor of the circular swimming pool whose radius is 7 m has to be cemented at the rate of ₹ 18 per m². Find the total cost of cementing the floor.

Q. Circumference of a circle is approximately equal to ___diameter

1. 4 times
2. 5 times
3. 6 times
4. 3 times

Q. Find the circumference of a circle whose diameter is 21 units.

1. 33 units
2. 66 units
3. 90 units
4. 45 units

Q. Find the circumference of the circles, given that:
(a) radius= 21 mm
(b) diameter= 14 cm

Q. Find the perimeter of a semicircle with a radius of 7 cm. $(\pi =\frac{22}{7})$

1. 36 cm
2. 22 cm
3. 154 cm
4. 14 cm

Q.

If the circumference of a circle with diameter 1 unit is about 3.14 units,

Then calculate the approximate length of the circumference of a circle that has:

a. 1.5 cm diameter b). 3.5 cm diameter c). radius is 1.62 cm

Q. the diameter of a bicycle wheel is 28cm.

• what distance will it cover in 100 revolutions.
• how many revolutions will it make to travel 352m.

Q. Perimeter of a circle is called its

1. radius
2. area
3. diameter
4. none of these

Q. If the radius of a circle is increased by 3%, calculate the percentage increase in the area of the circle? (round off to 2 decimal places)

1. 4.04%
2. 8.16%
3. 6.09%
4. 10.25%

Q. The diameter of a cars tyre is 70cm.Find the distance covered by it in 5 rounds(use pi=22)
7

Q. What is the diameter of a circle if its circumference is $80cm$?