《测定电源电动势和内阻》实验是电学的重要实验之一。实验电路可采用电流表的内接法和外接法,这两种电路连接从误差角度分析各有优缺点,通常实验采用电流表的外接,是为了使电源内阻测量误差更小,如果实验要求电源电动势 “Test the power of electromotive force and internal resistance” experiment is one of the important experiments of electricity. Experimental circuit can be used in ammeter internal and external methods, these two kinds of circuit connection from the error angle analysis of their own advantages and disadvantages, usually the use of ammeter outside the test, is to make the power supply internal resistance measurement error is smaller, if the experiment requires power EMF