In the adjoining figure, O is the center of the circle, and a semicircle is drawn on OA as the diameter. ∠APQ = 20°. The degree measure of ∠OAQ is :

1. 25°

2. 40°

3. 50°

4. 65°

In the given diagram, O is the center of the circle, and PQ is a tangent at A. If ∠ABC = 50°, then values of x, y and z respectively are :

1. 50°, 100°, 40°

2. 50°, 50°, 65°

3. 40°, 80°, 50°

4. 50°, 25°, 78°

A cylindrical metallic wire is stretched to double its length. Which of the following will NOT change for the wire after stretching?

1. Its curved surface area

2. Its total surface area

3. Its volume

4. Its radius

A right circular cone has the radius of the base equal to the height of the cone. If the volume of the cone is 9702 cu. cm, then the diameter of the base of the cone is :

1. 21 cm

2. 42 cm

3. $21\sqrt{7}$ cm

4. $2\sqrt{7}$ cm

$\Big[\text{Use } \pi = \dfrac{22}{7}\Big]$