在能够引入磁标势的区域内 ( )
A:
，
B:
，
C:，
D:
，
A:
，B:
，C:
，D:
，
举一反三
- 变化的磁场激发的感应电场满足 ( ) A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/f636147417d144a4ba1c35b5c019b5bd.png" />,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/c85cf7ff1a2b4ac1a1690f3c06424b52.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/d249e3e9419547bb942b3e012cb266ac.png" />,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/a53d71dd9ba14f6889f4a46ecb00b923.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/466f114b82234936ab3612322e18ae5b.png" />,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/a5968023d69c492a9d3559f5a59d81ba.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/836158ae6c8944a780cf31e1deb309a0.png" />,<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/9b1930e33b5e4af78f37e7d0ca350c2d.png" />
- 下列结论中正确的是 ( ) A: 若数列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/10b6bba1227b44138c6e945a1ed39646.png" />收敛, <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/803155493fdb46e9b6b97337cac5963f.png" />发散, 则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/b76a24d54cd14797b9d73350fb8fd255.png" />和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/44f12c63e34f42de8a3d486c40cc0f8b.png" />均发散 B: 若数列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/0ecfc168d33a4819870d7deec580bf4d.png" />与<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/2b6a72dab9df455b8483d47797e10ca2.png" />收敛, 则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/96d1b9dbd68b4aa69eecfb1e7180d366.png" />和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/2879af37195b495cb749871dcb11bf75.png" />均收敛 C: 若数列<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/85b08f06cfec4fa6a7f1e4758789a28f.png" />与<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/f19f0281807047ca99dab5b88bbc3e32.png" />发散, 则<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/a0fa01d49100430a939dedf78ec71ea7.png" />和<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/7634f23c1d5946dba3898912cd26e639.png" />均发散 D: 若<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/4540a2e9908b4300b71f780481e0cfbf.png" />, 则必有<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/39287aa060f74d46a6d7fd3b54fd24b3.png" />或<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/b19925d5d7114e3398d729bb58d6fc4a.png" />
- 空心圆轴的外径为D，内径为d，<img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/c268745e2545426ca7e4f20847abad16.png" />=d /D。其抗扭截面系数为（ ）。 A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/c8afd0b0bde9471e9174ef404bfa0bd3.png" /> ； B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/0d280ef40b30438aacd3ab8ee129a3d2.png" /> ； C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/263e7ba4c4c24cdd853583eb10f4e0cb.png" /> ； D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/54112e744a1e487fa709a47f5a78160d.png" /> 。
- 进行轴心受压杆的设计时，合理的截面形式是根据 原则确定的。（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/351866917b1d4286b2f3c9fec7fb4b67.png" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/bee3290fbc9f4da78075a187033cef2c.png" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/08d9d0f06d4f4b2396e343d5052d59f4.png" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/07a2642ce15b4516b2290e87fb1a371d.png" />
- 压弯构件临界状态时，截面上的应力分布可能有三种情况，不可能出现的情况为(图中“+”表示拉应力，“—”表示压应力)（ ） A: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/3488e21be56c455b8ab3263070b4ea2a.PNG" /> B: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/f94fd3e7151945f7855de94519f45701.PNG" /> C: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/76e3865bfbdf440b82dcd3ef1c7bf851.PNG" /> D: <img src="https://image.zhihuishu.com/zhs/doctrans/docx2html/202110/2b9fe89b8e3a4c9c928bc7abbcdf91f4.PNG" />