Tension is the magnitude of the pulling force exerted by a cable, string, chain or any similar object which pulling another object. Tension is basically the final common application of Newton’s law. Tension arises in the ropes or cables, when one object is pulled by another object using it to transmit the force. The force experienced by the object is called Tension force.
In the above figure Tension ‘T’ occurs when objects is pulled either side by rope.
Tension is a vector quantity, which has both magnitude and direction. Its magnitude remains constant at all points of the string. Tension is a force so it has the same unit that is Newton.
if we hold a block of weight W attached to the end of the string as in the figure:
Here, W is the weight of the block and T is the tension. When the body is at rest the magnitude of tension is equal to the weight of the body suspended by the string. Weight and the tension acts in the opposite direction.
So that, T = W.