Simple Pendulum

A simple pendulum consists of a small metallic ball suspended from a rigid stand by a thread. The metallic ball is called the bob of the pendulum. When the bob of the pendulum is released after taking it slightly to one side, it begins to move to and fro motion of a simple pendulums is an example of a periodic or an oscillation when its bob, starting from the mean position B, moves to A, to C and back to O. The pendulum also completes one
oscillation when its bob moves from one extreme position A to the other extreme position C and comes back to A. The time taken by the pendulum to complete one oscillation is called its
time period.

Fragmentation

Fragmentation is a type of asexual reproduction organisms like 

algae, star fish, and coral. The organism matures and gets broken up into two or more fragments or pieces. Which is developed into new individuals and live an independent life. After it mature the same process happens.

WORKING OF AN ELECTRIC BELL

                              

Electric bell consists of a coil of wire wound on an iron piece.The coil acts as an electromagnet.An iron strip with a hammer at one end is kept close to the electromagnet.There is a contact screw near

near the iron strip.When the iron strip is in contact with the screw,

the current flows through the coil which becomes an electromagnet.

It, then, pulls the iron strip.In this process, the hammer at the end of the strip strikes the gong of the bell to produce a sound.However,

when the electromagnet pulls the iron strip,it also breaks the circuit.

The current through the coil will stop flowing.It is no longer an electromagnet.It no longer attracts the iron strip.The iron strip comes back to its original position and touches the contact screw again. This completes the circuit.The current flows in the coil and the hammer strikes the gong again.This process is repeated in quick

succession.The hammer strikes the gong every time the circuit is completed.This is how an electric bell works.