In this paper, we investigated the effect of annealing temperature on the electrical and magnetic properties of polycrystalline Nd0.7Ca0.3MnO3 synthesized using the well-known solid-state reaction technique. After the formation of the required Perovskite crystal structure phase, another annealing treatment has been done. The selected annealing temperatures are 700, 800, and 900°C for 12 hours. Structural refinement of the X-ray diffraction patterns showed the formation of a single orthorhombic crystal structure phase the of P b n m space group in Nd0.7Ca0.3MnO3 without any impurity peaks. From magneto-resistance measurements, we found that NCMO samples have high-colossal magnetoresistance (CMR). Moreover, the under-investigated NCMO samples showed a high power factor. The resistivity data in the insulating region (T \u3eTMI) were analyzed by considering, the Mott-variable range hopping model. The phase transition temperature showed dependence on the grain size, where Curie temperature (TC) increases with an increase in the grain size
