@meghna , running time of Dijkstra's algo depends on which data structure we use to store information...
1) using Array data structure , running time $\in$ $O(|V|^{2})$
2) using Binary Heap data structure , running time $\in$ $O((|E|+|V|)(lg|V|))$
3) using Fibonacci Heap data structure , running time $\in$ $O(|E|+|V|(lg|V|))$