Online Test — Circles (Basics)
10 Questions • 20 min • Chapter MCQ
20:00
Question 1 of 10
easy
Radius = 5 cm. What is the diameter?
2.5 cm
5 cm
10 cm
15 cm
Explanation: Diameter = 2 x radius = 2 x 5 = 10 cm
Question 2 of 10
easy
Circumference = 44 cm (pi = 22/7). Find the radius.
3.5 cm
7 cm
14 cm
21 cm
Explanation: 2 x (22/7) x r = 44 => r = 44 x 7 / (2 x 22) = 7 cm
Question 3 of 10
medium
Find the area of a circle with radius = 14 cm (pi = 22/7).
88 cm^2
176 cm^2
616 cm^2
1232 cm^2
Explanation: A = (22/7) x 14^2 = (22/7) x 196 = 22 x 28 = 616 cm^2
Question 4 of 10
easy
Diameter = 20 cm. Find the circumference. (pi = 3.14)
31.4 cm
62.8 cm
125.6 cm
314 cm
Explanation: C = pi x d = 3.14 x 20 = 62.8 cm
Question 5 of 10
medium
Semicircle radius = 7 cm. Find its area. (pi = 22/7)
38.5 cm^2
77 cm^2
154 cm^2
308 cm^2
Explanation: Full circle area = (22/7) x 49 = 154 cm^2. Semicircle = 154/2 = 77 cm^2.
Question 6 of 10
easy
A chord is defined as:
A line through the centre
A line joining any two points on the circle
The distance around the circle
Half of the diameter
Explanation: A chord connects any two points on the circle. If it passes through the center, it is a diameter.
Question 7 of 10
medium
Circle area = 78.5 cm^2 (pi = 3.14). Find the radius.
2.5 cm
5 cm
10 cm
25 cm
Explanation: pi x r^2 = 78.5 => r^2 = 78.5/3.14 = 25 => r = 5 cm
Question 8 of 10
hard
Quarter circle has radius = 8 cm. Find its perimeter. (pi = 3.14)
12.56 cm
16 cm
28.56 cm
32 cm
Explanation: Arc = (pi x r)/2 = (3.14 x 8)/2 = 12.56 cm. Plus 2 straight sides = 2 x 8 = 16 cm. Total = 28.56 cm.
Question 9 of 10
medium
Wheel radius = 35 cm. Distance covered in 10 rotations? (pi = 22/7)
110 cm
220 cm
1100 cm
2200 cm
Explanation: Circumference = 2 x (22/7) x 35 = 220 cm. For 10 rotations: 220 x 10 = 2200 cm.
Question 10 of 10
medium
Two circles have radii 3 cm and 6 cm. What is the ratio of their areas?
1:2
1:3
1:4
2:3
Explanation: Area is proportional to r^2. Ratio = 3^2 : 6^2 = 9 : 36 = 1:4.