Q. 136. The volume of the cuboid whose length, breadth and height is 12 cm, 8 cm and 6 cm, is:
(A) 568 cu. cm
(B) 576 cu. cm
(C) 576 sq. cm
(D) 570 cu. cm
Answer:
(B) 576 cu. cm
Explanation:
The volume of a cuboid is calculated as Length $\times$ Breadth $\times$ Height. Here, $12 \times 8 \times 6 = 576$ cubic cm.
Q. 137. The area of a circle is $154~cm^2$. Its diameter is:
(A) 7 cm
(B) 14 cm
(C) 21 cm
(D) 28 cm
Answer:
(B) 14 cm
Explanation:
The area formula is $\pi r^2 = 154$. Substituting $\pi$ as $22/7$ gives $(22/7) \times r^2 = 154 \rightarrow r^2 = 49 \rightarrow r = 7$ cm. Since the diameter is twice the radius, $d = 14$ cm.
Q. 138. A line segment drawn perpendicular from the vertex of a triangle to the opposite side is called the:
(A) Bisector
(B) Median
(C) Perpendicular
(D) Altitude
Answer:
(D) Altitude
Explanation:
In geometry, a line segment drawn from a vertex of a triangle perpendicular to the opposite side (or its extended base) is formally called the altitude of the triangle.
Q. 139. The tangents drawn at the extremities of the diameter of a circle are:
(A) Perpendicular
(B) Parallel
(C) Equal
(D) None of the above
Answer:
(B) Parallel
Explanation:
Tangents drawn at the two opposite endpoints of a diameter are perpendicular to the diameter at those points. Because they are both strictly perpendicular to the same straight line, they must be parallel to each other.
Q. 140. If at some instant, the length of the shadow of a pole 30m high is m, then the angle of elevation of the sun is:
(A)
(B)
(C)
(D)
Answer:
(B)
Explanation:
Let be the angle of elevation. . The specific angle whose tangent is is .
