1. Area of a circle whose radius is “a” cm is:
(A) 2πr
(B) 2πa
(C) πa²
(D) 2πa²
2. Circumference of a circle whose radius is 1/2 cm is equal to:
(A) 2π
(B) 2πr
(C) πr/2
(D) r/2
3. Area of a sector of 60° in a circle of radius 6 cm is:
(A) 6π
(B) 12π
(C) 36π
(D) 3π
4. The space enclosed between two concentric circles is called:
(A) Cone
(B) Ellipse
(C) Annulus
(D) None of these
5. Arc of circle with diameter “d” is:
(A) πd
(B) 2πd
(C) πd/2
(D) None of these
6. If R and r denote the radii of the outer and inner circles, then area of annulus (ring) is:
(A) π(R² − r²)
(B) 2π(R² − r²)
(C) π(R + r)²
(D) (R² − r²)
7. If 2a and 2b are the major and minor axis of the ellipse, then area of ellipse is:
(A) ab
(B) πab
(C) (πab)/2
(D) 2πab
8. If 2a and 2b are the major and minor axis of the ellipse, the circumference of the ellipse is:
(A) π(a + b)
(B) π(a − b)
(C) 2π(a + b)
(D) 2π(a − b)
9. If the area of a circle is 16π, then radius r is:
(A) 4
(B) 2
(C) 16
(D) 8
10. If x and y are the major and minor axis of the ellipse, then area is:
(A) (πxy)/2
(B) (πxy)/4
(C) πxy
(D) 2πxy
11. The circumference of a pulley is 440/7 cm, its diameter is:
(A) 20 cm
(B) 40 cm
(C) 80 cm
(D) 10 cm