A toy is in the shape of a solid cylinder surmounted by a conical cap. If the height and diameter of the cylindrical part are 21 cm and 40 cm respectively, and height of the cone is 15 cm , find the total surface area of the toy.
In the figure, find the area of the shaded region. enclosed between two concentric circles of radii 7 cm and 14 cm where ∠AOC= 40 ° .
An aquarium is in the form of a cuboid whose external measures are 80cm×30cm×40cm. The base side faces and back face are to be covered with colored paper. Find the area of the paper needed?
A well of diameter 140 cm has a stone parapet around it. If the length of the outer edge of the parapet is 616 cm, what is the width of the parapet?
A sector is cut from a circular sheet of radius 100 cm, the angle of the sector being 240°. If another circle of the area same as the sector is formed, the radius of the circle of the new radius is
The density of 2 M aqueous solution of NaOH is 1.28 g/cm3. The molality of the solution is [Given that molecular mass of NaOH = 40 g mol-1]
An object 1 m tall is placed on the principal axis of a convex lens and its 40 cm tall image is formed on the screen placed at a distance of 70 cm from the object. The focal length of the lens.
A plane mirror ‘M’ and a concave mirror ‘X’ are kept at a separation of 40 cm with their reflecting faces facing each other as shown in figure. An object AB is kept perpendicular to the principal axis in position (1). Considering successive reflections first at mirror ‘X’ and then at ‘M’, a real image is formed in front of ‘M’ at a normal distance 8 cm from it. If the object is moved to new position (2), the real image is formed at 20 cm from ‘M’ with the reflections as described earlier.
The number of possible natural oscillations of air column in a pipe closed at one end of length 85 cm whose frequencies lie below 1250 Hz are (Velocity of sound = 340 m s-1)
