5．1千欧、0．25W.82欧、1W的两只金属碳膜电阻,计算使用时各电阻上的电压,电流最大值是多少.

p=i2r 0.25=i2 x 1000 i2=0.25/1000 i= sqrt(0.25/1000)v = ir = 1000 x sqrt(0.25/1000)1 = i2 x 82 i2= 1/82 i = sqrt(1/82)v = ir= 82 x sqrt(1/82)= sqrt(82)