Surface Areas and Volumes

For a sphere of radius r, curved surface area of the hemisphere

• $2\pi r^2$

• $3\pi r^2$

• $4\pi r^2$

• $\pi r^2$

Consider a hollow cylinder having external radius R, internal radius r and height h. Volume of the material

• $\pi r^2h$

• $\pi\left(R^2-r^2\right)h$

• $\pi\left(R-r\right)^2h$

• $\pi\left(h^2-r^2\right)R$

A cone is cut through a plane Parallel to it's base and then the cone is formed on one side of that plane is removed. The new part that is left over on the other side of the plane is called

• Frustum of sphere

• Frustum of cone

• Frustum of pyramid

• Frustum of cylinder

Area of each end in right circular hollow cylinder

• $\pi\left(R^2-r^2\right)$

• $2\pi\left(R^2-r^2\right)$

• $\pi r^2$

• $2\pi r^2$

A surahi is the combination of

• a sphere and a cylinder

• a hemisphere and a cylinder

• a hemisphere and a cone

• a cylinder and a cone

A ................ is a solid or a hollow object that has a circular base and a circular top of the same size

• Cylinder

• Cone

• Sphere

• Hemisphere

What is the formulae for volume of the frustum of the cone?

• $\pi\left(r_1+r_2\right)l$

• $\frac{1}{3}\pi h\left(r_1^2+r_2^2+r_1r_2\right)$

• $\frac{1}{3}\pi l\left(r_1^2+r_2^2+r_1r_2\right)$

• $\pi h\left(r_1^2+r_2^2+r_1r_2\right)$

The radius of a wheel is 0.25m. The number of revolutions it will make to travel a distance of 11km is

• 6500

• 7000

• 6050

• 7500

In a right circular cone, the cross section made by a plane parallel to the base is a ?

• circle

• frustum of cone

• sphere

• hemisphere

What is the formulae for curved surface area  of the frustum of the cone?

• $\pi\left(r_1+r_2\right)l$

• $\frac{1}{3}\pi h\left(r_1^2+r_2^2+r_1r_2\right)$

• $\frac{1}{3}\pi l\left(r_1^2+r_2^2+r_1r_2\right)$

•  $\pi\left(r_1+r_2\right)h$