数控车床理论考试试题liang

For personal use only in study and research; not for commercial use蚈数控车床理论考试试卷羅一、选择：<20题，每题1分）20分莃1、

Forpersonaluseonlyinstudyand research;notforcommercialuse 数控车床理论考试试卷蚈一、选择：<20题，每题1分）20分羅 1、表面粗糙度波形起伏间距λ和幅度h的比值λ/h一般应为<A）. 莃 (A><40 芁 (B>40—1000 膅 (C>>1000 蚃 (D>>2400 33 2、纯铜为紫红色,密度为8.96×10kg/m,熔点为<B）. 蒃 (A>1187℃ 蒇 (B>1083℃ 袇 (C>1238℃ 蒂 (D>1038℃ 薃 3、齿轮传动效率较高,一般圆柱齿轮的传动效率为<C）. 袈 (A>85%-90% 芅 (B>90%-95% 薅 (C>95%-98% 蚃 (D>98%-99% 艿