One of the key challenges in Wireless Sensor Network (WSN) is to minimize energy consumption by each sensor node and increase network lifetime. Sensor network consist of huge number battery powered sensor nodes. It is difficult to recharge these nodes. So, to achieve an appreciable network lifetime, energy consumption of the node should be minimum. By finding the energy efficient route for data transmission network lifetime can be maximized. Cluster based routing protocols are the standard approach for achieving efficient and scalable performance in WSN. Also, there are problem in some approaches such as in static WSN, in which sensor nodes transfer their data to static sink in a multi-hop manner which causes network partition problem known as "Hot Spot Problem" In case of WSN with mobile sink, as sink travels for data collection from CHs, the load on sink node increases which leads to increase in energy consumption of sink. In this paper a proposed approach is to overcome these problems. The proposed approach uses node mobility to solve these problems. In this approach, mobile sink is used with few mobile nodes. If these mobile nodes are efficiently mobilized then the hot spot problem, as well as sink load problem can be tackled. The movement of mobile nodes is decided on the basis of their distance from CHs. By using node mobility with mobile sink helps to increase the network lifetime and energy efficiency of the network.