Change in entropy of non-spinning black holes w.r.t. the radius of event horizon in XRBs

The present research paper discusses the derivation for the change in entropy of Non- spinning black holes with respect to the change in the radius of event horizon applying the first law of black hole mechanics ( $delta M = frac{kappa}{8pi} delta A + varOmegadelta J - upsilondelta Q$ ) with the relation for the change in entropy δS=8πMδM. When the work is further extended with proper operation, the entropy of black hole is obtained almost the same as the Bekenstein-Hawking entropy of black hole. This is the entirely new method to obtain the change in entropy of Non-spinning black holes w.r.t. the radius of event horizon and Hawking entropy of black hole. We have also calculated their values for different types of test non-spinning black holes having masses 5–20M _⊙ found in X-ray binaries (Narayan, gr-qc/0506078v1, 2005).