[填空题]
A bird stands on a dc electric transmission linpfy nf4jg6g ,yl;2c9o e carryingv 14o g/qjygx) 2800 A (Fig. 18–34). The line hxv qjg1g 4)/oyas $2.5\times10^{ -5}\;\Omega$ resistance per meter, and the bird’s feet are 4.0 cm apart. What is the potential difference between the bird’s feet? $ \times10^{-3 }\;V$