Question

A potted plant kept in a room tends to bend towards the direction pf light . This movement is called

Answer 1

it is called as tropism

the movement of plant towards or away from the stimuli is tropism.

the movement of a plant part is in response to light it is called as phototropism.
hope it helps.

Answer 2

A potted plant kept in room bend towards direction of light known as phototropism.

Explanation:

The movement of plants in response to light is called as phototropism. Apart from plant this phenomenon is exhibited by certain species of fungi too. The plant hormone called as Auxin gets excited when it receives light and tends to elongate and move in the direction in which it receives light.  

Phototropism is an external stimulus and when it happens towards light is called as positive phototropism and when it happens away from light is called as negative phototropism.