The sun is a main sequence G2V star, based on Hertzsprung-Russel(H-R)diagram classification. Earlier studies have shown that the temperature of the core is about 15 MK and as we move away from the core, temperature decreases from 15 MK to 5800 K at photosphere. There is anomalous variation of temperature after photosphere, it starts increasing for further layers and there is abrupt change in temperature from transition region to corona. After the corona, temperature decreases again slowly. The temperature of the corona is found millions of kelvin higher than that of the surface temperature....