Is there a relationship between the electric field [img=14x24]1803a376c9db0a5.png[/img] and magnetic field [img=14x24]1803a376d21ab6b.png[/img] of an electromagnetic wave at each point in vacuum?
A: No any relationship.
B: Yes, [img=14x24]1803a376db08c62.png[/img] is perpendicular to [img=14x24]1803a376e3d9bc3.png[/img] and [img=59x19]1803a376eca6699.png[/img].
C: Yes, [img=14x24]1803a376db08c62.png[/img] is parallel to [img=14x24]1803a376e3d9bc3.png[/img] and [img=59x19]1803a376eca6699.png[/img].
D: No relationship in direction but [img=59x19]1803a376eca6699.png[/img] in magnitude.
A: No any relationship.
B: Yes, [img=14x24]1803a376db08c62.png[/img] is perpendicular to [img=14x24]1803a376e3d9bc3.png[/img] and [img=59x19]1803a376eca6699.png[/img].
C: Yes, [img=14x24]1803a376db08c62.png[/img] is parallel to [img=14x24]1803a376e3d9bc3.png[/img] and [img=59x19]1803a376eca6699.png[/img].
D: No relationship in direction but [img=59x19]1803a376eca6699.png[/img] in magnitude.
举一反三
- What is the net force on a magnetic dipole in a uniform magnetic field [img=14x24]1803a3749667c37.png[/img]? A: Nonzero and in the direction of [img=14x24]1803a3749f40258.png[/img]. B: Nonzero and in the direction of [img=28x26]1803a374a7784ea.png[/img]. C: Nonzero and perpendicular to [img=14x24]1803a3749f40258.png[/img].[img=14x24]1803a3749f40258.png[/img] D: zero.
- 其他条件不变时，当税收增加[img=14x24]17e43c3ac2c6638.png[/img]时,IS曲线( ) 未知类型：{'options': ['左移[img=14x24]17e43c3ac2c6638.png[/img]', ' 左移[img=14x24]17e43c3ac2c6638.png[/img] X税收乘数', ' 右移[img=14x24]17e43c3ac2c6638.png[/img] X税收乘数', ' 右移。'], 'type': 102}
- 设X为随机变量，且E(X)= −1,Var(X)=3，则[img=136x31]1803b3be69ca3f3.png[/img] A: 18 B: 9 C: 30 D: 14
- 逻辑函数F=AB+[img=14x24]17e43db17bde337.jpg[/img]D，其反函数[img=12x24]17e43db184fa8ba.jpg[/img]为（ ） 未知类型：{'options': ['（A+B）（[img=14x24]17e43db18d92bfb.jpg[/img]+[img=14x24]17e43db196a9131.jpg[/img]）', ' （[img=14x24]17e43db17bde337.jpg[/img]+B）（[img=14x24]17e43db18d92bfb.jpg[/img]+D）', ' （A+[img=14x24]17e43db1a047788.jpg[/img]）（C+[img=14x24]17e43db196a9131.jpg[/img]）', ' （A+B）（C+D）'], 'type': 102}
- Electric field [img=14x24]1803a374c4e0b52.png[/img] and magnetic field [img=14x24]1803a374ccd1dcd.png[/img] are perpendicular to the particle’s velocity and to each other as shown in the figure. What is the speed that the particles must have when they leave the source for them to be able to pass through the very narrow and long field region? . (In form of / , if fraction)