# Free Circles 01 Practice Test - 4th Grade

The ____ divides the circle into two equal parts.

A.

Diameter

B.

Radius

C.

Circle

D.

Circumference

#### SOLUTION

Solution : A

The diameter divides a circle into two equal parts. The statement "Length of chord is always greater than radius" is

A.

True

B.

False

#### SOLUTION

Solution : B

The length of the chord need not always be greater than the radius. Consider the figure, OP is the radius, AB is the chord.

OP = 5 cm, AB = 2 cm What will be the diameter of a circle whose radius is 15cm?

A.

5cm

B.

30cm

C.

45cm

D.

15cm

#### SOLUTION

Solution : B

Radius =  15 cm
Diameter =2×radius
= 2×15
= 30 cm

In a circle of radius 6cm, which of the following cannot be the length of a chord?

A.

8cm

B.

10cm

C.

14cm

D.

12cm

#### SOLUTION

Solution : C

In a circle of radius 6cm, the diameter will be 12 cm.
A chord is a line segment with its endpoints on the circle and we know that diameter of a circle is the largest chord of the circle.
So a chord cannot be longer than 12cm.

If the diameter of a circle is 32 cm, its radius is equal to ___ .

A.

14 cm

B.

16 cm

C.

18 cm

D.

32 cm

#### SOLUTION

Solution : B

Given that

The diameter of a circle = 32 cm

The radius of a circle = Diameter2

On substituting the values we get:

The radius of the circle whose diameter is 32 cm =322=16 cm

A circle with center O is shown. AB in the figure is a : A.

Diameter

B.

Radius

C.

Chord

D.

Tangent

#### SOLUTION

Solution : C

A chord of a circle is a line segment whose endpoints lie on the circle.

The diameter of a circle is the chord which passes through the center of the circle.

The line segment AB is a chord as it does not pass through the center of the circle.

Which of the following is not a radius of the circle with center O? A.

OA

B.

AB

C.

OC

D.

OD

#### SOLUTION

Solution : B

The radius of a circle is a line segment connecting the center of the circle to any point on the circumference of the circle.

So, OA, OC, OD and OB are the radii of the given circle.

However, AB is the diameter.

Which of the following represent the diameters of the circle with center O? A.

OP, OB

B.

OQ, AB

C.

OB, PQ

D.

AB, PQ

#### SOLUTION

Solution : D

The diameter of a circle is a line segment which passes through the center of the circle and whose endpoints lie on the circle.

AB and PQ are the diameters of the circle.

Find the radius of a circle whose diameter is 96 cm.

A.

192 cm

B.

42 cm

C.

48 cm

D.

45 cm

#### SOLUTION

Solution : C

Given that

The length of the diameter of a circle = 96 cm

We know that, radius of a circle = Diameter2

On substituting the values we get:

Radius of circle = 962=48 cm

What will be the radius of a circle  whose diameter is 20 cm?

A.

10 cm

B.

15 cm

C.

20 cm

D.

40 cm

#### SOLUTION

Solution : A

Given that

The diameter of a circle = 20 cm

The radius of a circle = Diameter2

On substituting the values we get:

The radius of the circle = 202=10 cm