A: E/3
B: E/9
C: E
D: 3E
E: E/16
举一反三
- Both electric field E and electric potential V can describe the characteristics of a field. If the electric potential at a certain point is zero, the electric field at that point has to be zero.
- The Biot-Savart Law is used to（ ） A: determine the magnetic field created by an electric current B: determine the electric field created by an electric current C: determine the force field created by an electric current D: determine the magnetic field created by individual point charges E: determine the electric field created by individual point charges
- The<br/>Biot-Savart Law is used to A: determine<br/>the electric field created by individual point charges B: determine<br/>the electric field created by an electric current C: determine<br/>the magnetic field created by individual point charges D: determine<br/>the magnetic field created by an electric current E: determine<br/>the force field created by an electric current
- There are two point-charges<br/>q1<br/>and q2.<br/>The magnitude of electric field force between them is F. If the third<br/>point charge +Q is<br/>introduced, will the force between q1<br/>and q2<br/>be influenced by +Q<br/>[ ] A: It will not be influenced by +Q B: It will be influenced by +Q
- Electric field lines A: are trajectories of a test charge B: are vectors in the direction of the electric field C: form closed loops D: cross each other in the region between two point charges E: are none of the above
内容
- 0
Microwave oven uses electromagnetic wave to heat food. Suppose the space inside the oven can be treated as free space. If the electric field at point P in the oven is measured to be [img=144x45]18033d924610386.png[/img], then the magnetic field at point P at the same moment is B=_________T.
- 1
It is found more convenient to adopt the point of view that a moving charge sets up a magnetic field, _____ that this field exerts a force on another charge moving through it. A: and B: or C: that D: but
- 2
Three point charges Q1,Q2,Q3 are in space. S is a closed surface. Q1 is outside S while Q2 and Q3 are inside. E is the magnitude of the electric field at an arbitrary point on surface S and [img=23x22]1802eac9be6643b.png[/img] denotes the electric flux through S. Which of the following statements is correct?[img=103x84]1802eac9c979d7f.png[/img] A: Both E and FE depend on Q1,Q2,Q3 . B: Both E and FE depend on Q2,Q3 . C: E depends on Q1,Q2,Q3 while FE depends on Q2,Q3 . D: E depends on Q2,Q3 while FE depends on Q1. Q2,Q3 .
- 3
The radius of a uniformly charged conducting sphere is R and the charge quantity is Q. The electric field intensity inside the conductor is A: 0 B: [img=72x67]1803b96ae92dd57.png[/img] C: [img=85x67]1803b96af174e3e.png[/img] D: [img=81x63]1803b96af9c0a88.png[/img]
- 4
测量公式正确的是： A: L=q x E B: L= q/E C: E= q x L D: q=E/L