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.