The Investigation on the Sensitivity and Error of Single Bridge

By using two kinds of methods the formula on the relative sensitivity of single bridge is given. All factors affecting relative sensitivity are analyzed. The sensitivity of slide bridge and its influence on the measured resistance R_x are discussed. The condition of the minimum relative error is theoretically given. That is the place of the balance point should be chosen according to the ratio of the measured resistance R_x to the internal resistance R_g of the galvanometer in order to get the minimum relative error. Thereby, the theoretical evidence is offered to cut down experimental error by choosing best ratio N.