Circumference

Q. The length of a road roller is 2.1m and its diameter is 1.4m. For levelling a ground 500 rotations of the road roller were required. How much area of ground was levelled by the road roller? Find the cost of levelling at the rate of Rs. 7 per sq. m.

Q.

The radius of a circle is double of its diameter.

1. True

2. False

Q. What is the circumference of a circle with diameter 28 cm?

1. 14 cm
2. 88 cm
3. 44 cm
4. 176 cm

Q. If diameter of a road roller is 0.9 m and its length is 1.4 m, how much area of a field will be pressed in its 500 rotations ?

Q.

The length of the minutes hand of a wall clock is 6cm. find the distance covered by the tip of the minutes hand in 25 minutes.

Q.

Circumference of a circle of diameter $5\mathrm{cm}$is-

1. $3.14\mathrm{cm}$

2. $31.4\mathrm{cm}$

3. $15.7\mathrm{cm}$

4. $1.57\mathrm{cm}$

Q. The diameter of roller 1.5 m long is 84 cm. If it takes 100 revolutions to level a playground, find the cost of levelling this ground at the rate of 50 paise per square metre.

Q.

Estimate the circumference of the circular base of the object.

• Tube of lip balm with radius 0.5 mm

Q. The diameter of a circular flower garden is 70 m. What is the cost of fencing it, at ₹20 per metre ?

1. ₹4600
2. ₹4800
3. ₹4400
4. ₹4200

Q.

A wheel of radius 20 centimetres rolls along. How much would it move ahead after 10 rotations?

Q.

The length of the complete circle is called the __ of the circle.

Q.

The number of diameters that can be drawn in a circle are

Q.

The length around the boundary of a complete circle is called __ of the circle.

1. circumference
2. Perimeter
3. Area
4. Closed surface area

Q.

What is the locus of centers of all circles passing through point $A$ and Point $B$, which are two fixed points in a plane?

Q.

The circumference of a circle of radius $r$ is given by ___.

1. $\pi r$

2. $2\pi r$

3. $4\pi r$

4. $\frac{\pi r}{2}$

Q.

A saucer has a radius of $8\mathrm{cm}.$ A plate has a radius of $12\mathrm{cm}.$ How much larger is the circumference of the plate than the circumference of the saucer?

Q.

The length of the boundary of a circle is called its

1. circumference

2. arc length

3. segment

4. none of these

Q. If a line intersects two concentric circles (circles with the same centre) with centre $O$ at $A,B,C$ and $D$, prove that $AB=CD$ (see figure)

Q. Two unequal spherical balls lie on a field touching each other. The radius of the smaller ball is $9cm$ and the point of contact is $12cm$ above the field. Find the sum of the radii of the two balls.

Q.

The circumference of a circle is 44 cm. What is its area?

1. 168 sq cm

2. 145 sq cm

3. 1.54 sq m

4. 154 sq cm

Q.

The length of the complete circle is called __ of the circle.

Q. The length of the complete circle is called___of the circle.

1. radius
2. circumference
3. chord
4. segmant

Q.

The radius of a circle if its perimeter and area are numerically equal is

1. 8 units

2. 5 units

3. 2 units

4. 4 units

Q. What does Pi means in circle ?

Q.

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

1. 88 cm

2. 120 cm

3. 8 cm

4. 132 cm

Q.

The perimeter of a circle is called its ____.

1. circumference

2. radius

3. area

4. diameter

Q.

Which of the following is equal to the length of the curve in red in the given circle?

1. Radius

2. Segment

3. Centre

4. Circumference

Q. The radius of a circle whose circumference is the sum of that of two circles with radii 36 and 20 units is __.

1. 46 units
2. 65 units
3. 56 units
4. 34 units

Q.

What is the approximate circumference of a circle that has a radius of 14 cm?

1. 57 Centimeters

2. 113 Centimeters

3. 38 Centimeters

4. 9 Centimeters

Q. Find the distance covered by the minute hand in 10 minutes if its length is 21 cm.
[3 Marks]