Draw a circle and any two of its diameter.If you join the ends of thes diameters,what is the figure obtained?What figure is obtained if the diameters are perpendicular to each others?How do you check your answer?

In a circle C(O,r), AOB and COD are two diameters perpendicular to each other. Find length of chord AC.

What is the perimeter of each of the following figures?What do you infer from the answers?

A wire of resistance 8R is bend in the form of a circle as shown in the figure. What is the effective resistance between the ends of the diameter AB?

Draw a circle of radius 3cm. Take two point P and Q on one of its extended diameter each at distance of 7cm from its centre. Draw tangents to the circle from these two points P and Q

Suppose you drop a die at random on the rectangular region shown in Fig. What is the probability that it will land inside the circle with diameter 1 m ?

Two diameters of a circle intersect each other at right angles. Prove that the quadrilateral formed by joining their end points is a square.

A resistance of 10 ohm is bent in the form of a closed circle. What is the effective resistance between the two points at the ends of any diameter of this circle?

A wire of resistance 20Ohm is bent in the from of closed circle.What is the effective resistance between two points at the ends of any diameter of the circle?

In a squared sheet, draw two triangles of equal areas such that the triangles are congruent. What do you say about its perimeters?

Two charged conducting spheres of radii a and b are connected to each other by a wire. What is the ratio of electric fields at the surfaces of the two spheres? Use the result obtained to explain why charge density on the sharp and pointed ends of a conductor is higher than on its flatter portions.