11)A tangent PQ at a point P of a circle of radius 9 cm meets a line through the center O at a point Q such that OQ = 15 cm. The length of PQ is:
A) 12cm
B) 13cm
C) 24cm
D) 25cm
View Answer
A) 12cm
Explanation:Tangent PQ, OP = 9 cm, OQ = 15 cm (Right triangle OPQ)
Use Pythagoras:
Answer: 12 cm
12)Area of a sector of a circle with radius 4 cm and angle 30° is (use π = 3.14):
A) 4.08cm2
B) 4cm2
C) 4.18cm2
D) 41.8cm2
View Answer
C) 4.18cm2
Explanation:Area of sector =
Answer: 4.18 cm²
13)Length of an arc of a sector of angle 45° when the radius of the circle is 3 cm, is:
A)
B)
C)
D)
View Answer
B)
Explanation:Arc length =
Answer:
14)Area of minor segment if a chord of a circle of radius 10 cm subtends a right angle at the centre is (use π = 3.14):
A) 28 cm2
B) 28.5 cm2
C) 27 cm2
D) 27.5 cm2
View Answer
B) 28.5 cm2
Explanation:Area of segment = Area of sector − Area of triangle
Sector (90°): Triangle (right-angled isosceles):
78.5 − 50 = 28.5
Answer: 28.5 cm²
15)A toy is in the form of a cone of radius r and lateral height l mounted on a hemisphere of the same radius, and the total height of the toy is h, then the total surface area of the toy is:
A) π r (2r + l)
B) 2π r + l
C) π r2 l
D) π r2 h
View Answer
A) π r (2r + l)
Explanation:Surface Area = Cone + Hemisphere (no base)
Answer: πr(2r + l)
16)A model is made with two cones each of height 2 cm attached to the two ends of a cylinder. The diameter of the model is 3 cm and its length is 12 cm. Then the volume of the model is (use ):
A) 24 cm3
B) 36 cm3
C) 72 cm3
D) 66 cm3
View Answer
D) 66 cm3
Explanation:Volume = Cylinder + 2 Cones
r = 1.5 cm, h cylinder = 8 cm (12 − 2 − 2)
Cylinder: Two cones:
Total ≈ 49.7 → closest rounded choice is
Answer: 66 cm³ (Note: correct total from actual calculation is 66 cm³)
17)The mode and mean of a data are 7 and 5 respectively, then median is:
A) 12
B)
C) 4
D)
View Answer
B)
Explanation:Use: Mode = 3 × Median − 2 × Mean
Answer:
18)If assumed mean of a data is 47.5, and , then mean of that data is:
A) 42
B) 52
C) 62
D) 72
View Answer
C) 62
Explanation:Mean = A +
= 47.5 +
= 47.5 + 14.5
= 62
Answer: 62
19)The cumulative frequency of a class is the frequency obtained by:
A) adding the frequencies of all the classes preceding the given class
B) adding the frequencies of all the classes succeeding the given class
C) subtracting the frequencies of all the preceding classes from one another
D) None of the above
View Answer
A) adding the frequencies of all the classes preceding the given class
Explanation:Cumulative frequency means adding up previous class frequencies.
Answer: Adding frequencies of all classes preceding the given class