1.空心圆截面外径为D，内径与外径比值为\alpha，其极惯性矩为()

A.<img src="https://cg-service.oss-cn-shanghai.aliyuncs.com/20240111/1704959826185499.png">

B.<img src="https://cg-service.oss-cn-shanghai.aliyuncs.com/20240111/1704959826207727.png">

C.<img src="https://cg-service.oss-cn-shanghai.aliyuncs.com/20240111/170495982622821.png">

D.<img src="https://cg-service.oss-cn-shanghai.aliyuncs.com/20240111/1704959826355817.png">

A.0.8

B.0.6

C.0.5

D.0（实心轴）

A.宽度的平方

B.高度的立方

C.高度的平方

D.宽度的立方

A.惯性矩减小一倍

B.惯性矩不变

C.惯性矩增加八倍

D.惯性矩增加四倍

A.2

B.4

C.1/2

D.1/4

A.2倍

B.4倍

C.8倍

D.16倍

A.2

B.4

C.6

D.8

A.空心钢轴的较大

B.实心铝轴的较大

C.其值一样大

D.其大小与轴的变模量有关

A.1/2

B.1/4

C.1/16

D.1/32