Free Circles 02 Practice Test - 4th Grade 

Question 1

The figure is of a circle with its center at O. The line PQ is the:

A.

Diameter of the circle

B.

Radius of the circle

C.

Chord of the circle

D.

Tangent of the circle

SOLUTION

Solution : A

The line PQ is the diameter of the circle. A diameter of a circle is a line segment that passes through centre of the circle and whose endpoints lie on the circle.

Question 2

Which is the correct relation of radius and diameter?

A.

r = 2D

B.

D = 2r

C.

r = D

D.

r = 3D

SOLUTION

Solution : B

Diameter = 2 × radius (or) twice the radius 
D = 2r is the correct relation between them.

Question 3

The region inscribed by a chord and two radii having endpoints at the end of the chord will be a/an ___.

A.

isosceles triangle

B.

scalene triangle

C.

square

D.

parallelogram

SOLUTION

Solution : A

The shaded triangle in the figure is an isosceles triangle.
A triangle in which two sides are equal is called an isosceles triangle. Here, the two equal sides are the radii of the circle OA and OB.

Question 4

Identify longest chords in the given figure.

A.

CD, AD

B.

AB, BC

C.

AB, CD

D.

BC, AD

SOLUTION

Solution : D

The chords of the given circle are AB, CD, BC and AD.

The diameter of a circle is its longest chord.

Since BC and AD pass through the center(O) of the circle, they are the diameters of the circle and hence, the longest chords.

Question 5

Which of the following cannot be the length of chord of a circle of radius 4 cm?

A.

12 cm

B.

6.5 cm

C.

6 cm

D.

7 cm

SOLUTION

Solution : A

Given that

The radius of a circle is 4 cm.

The diameter of the circle = 4 × 2 = 8 cm

The diameter is the longest chord of a circle. Hence, the length of any chord cannot be more than 8 cm.

Question 6

A circle with center O is shown below. The line segment OA is the ____ of the circle.

A.

diameter

B.

radius

C.

chord

D.

segment

SOLUTION

Solution : B

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

The line segment OA is the radius of the circle.

Question 7

Find the diameter of a circle of radius 48 cm.

A.

98 cm

B.

96 cm

C.

100 cm

D.

95 cm

SOLUTION

Solution : B

Given that

The radius of a circle = 48 cm

The diameter of a circle = radius × 2

On substituting the values we get;

The diameter of the circle = 48 × 2 = 96 cm

Question 8

What will be the radius of a circle  whose diameter is 36 cm?

A.

11 cm

B.

66 cm

C.

16 cm

D.

18 cm

SOLUTION

Solution : D

Given that

The length of the diameter of a circle = 36 cm

We know that, radius of a circle = Diameter2

On substituting the values we get:

Radius of circle = 362=18 cm 

Question 9

What will be the diameter of a circle of radius 18 cm?

A.

36 cm

B.

18 cm

C.

9 cm

D.

39 cm

SOLUTION

Solution : A

Given that

The radius of the circle = 18 cm

The diameter of the circle = radius × 2

On substituting the values we get:

The diameter of the circle = 18 × 2 = 36 cm

Question 10

If the radius of a circle is a multiple of 3, then the diameter will be a multiple of

A.

3

B.

6

C.

both 3 and 6

D.

5

SOLUTION

Solution : C

Given that

The radius of a circle is a multiple of 3.

So, the radius of the circle can be 3n, where n is any natural number.

Now, Diameter of a circle = radius × 2 = 3n × 2 = 6 ×n

Hence, the diameter of the circle is a multiple of both 3 and 6.