# 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:

Diameter of the circle

Radius of the circle

Chord of the circle

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?

r = 2D

D = 2r

r = 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 ___.

isosceles triangle

scalene triangle

square

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.

CD, AD

AB, BC

AB, CD

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?

12 cm

6.5 cm

6 cm

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.

diameter

radius

chord

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.

98 cm

96 cm

100 cm

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?

11 cm

66 cm

16 cm

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?

36 cm

18 cm

9 cm

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

3

6

both 3 and 6

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.