1、which one is vector field a、length b、velocity c、area d、energy
2、which one is not correct for gradient? a、gradient is one of the directional derivative b、the directional derivative of a scalar field at a certain direction is the projection of the gradient in the direction c、gradient is a scalar field d、gradient is the maximum spatial rate of change of the scalar field in a point
3、which one of the following equations is correct? a、 b、 c、 d、
4、which one of the following equations does not make sense? a、 b、 c、 d、
5、which one of the following formulas is identically zero? a、 b、 c、 d、
ch 3 static electric fields
unit 3 test
1、the parameter that can change the capacitace per unit length of the coaxial line is a、charge b、permittivity c、permeability d、voltage
2、which one is not the possible way to derive static electric field? a、potential function with boundary condition b、capacitance c、superposition from field element d、gauss's law
3、the electric field intensity of a positive point charge is inversely propotional to a、the charge b、the field position r c、the square of the field position r d、the third power of field position r
4、the boundary condition is the field a、inside the conductor b、inside the dielectric c、in the air d、on the interface of two media
5、the polarized surface charge density can be derived from a、 b、 c、 d、
ch 4 solution of electrostatic problems
unit 4 test
1、which one of the following equations is the poisson’s equation a、 b、 c、 d、
2、which of the following is not the boundary conditions of electric potential a、 b、 c、 d、
3、when the angle between two grounded conducting planes is 45°，in order to analyze the field when a positive point charge is between and close to these two planes，how many image charges we need? a、3 b、5 c、7 d、9
4、for the method of image, which one is not correct? a、the image charge is not real charge b、the induced charge is real charge c、for a positive point charge closed to a grouded conducting plane, the induced charge is only negative type. d、for a positive point charge closed to an ungrouded conducting sphere, the induced charge is only negative type.
5、uniqueness theorem is the therotical basis for the method of image
ch 5 steady electric currents
unit 5 test
1、the unit of volume current density is a、a/m b、 c、v/m d、
2、the parameter that can change the inductance per unit length of the coaxial line is a、current i b、permittivity c、voltage d、permeability
3、the boundary condition for steady electric field is a、e1n=e2n b、b1n=b2n c、j1n=j2n d、d1t=d2t
4、the steady electric field is a solenoidal field.
5、in steady electric field, the electric field intensity has only normal component on the surface of a conductor with finite conductivity.
ch 6 static magnetic fields
unit 6 test
1、the boundary conditon for static magnetic field is a、b1n=b2n b、e1t=e2t c、d1n=d2n d、h1n=h2n
2、the units of permeability of free space and magnetic flux density vector are a、a/m, h b、h/m, t c、v/m, h d、f/m, t
3、the relationship between magnetic field intensity and magnetic flux density vector is a、 b、 c、 d、
4、one of the parameters that can change the inductance per unit length of the coaxial line is current.
5、the magnitude of the magnetization vector is related to the material and the applied magnetic field.
ch 7 time-varying fields and maxwell'sequations
unit 7 test
1、which of the following is the potential function in time-varying fields? a、 b、 c、 d、
2、which one of the following is not instantaneous form of time-varying field? a、 b、 c、 d、
3、the induced electric field is irrotational field.
4、the displacement current is not real current.
5、the boundary conditions of time-varying fields are different from that of static fields.
ch 8 plane electromagnetic waves
unit 8 test
1、the phase difference between e and h in a good conductor is a、0 degree b、30 degrees c、45 degrees d、90 degrees
2、the uniform plane wave is a、te wave b、tm wave c、non tem wave d、tem wave
3、what is the polarized type of the electric field a、linear polarization b、left hand elliptical polarization c、right hand circular polarization d、right hand elliptical polarization
4、the average poynting vector for standing wave is non zero.
5、the phase constant of a em wave in fr4 with relative permittivity of 4.4 is smaller than that in air
final test
final test
1、the correct statement about method of image is a、method of image can not be applied to media interface b、to meet the boundary conditions, multiple mirror charges can be configured c、the position of the image charge can be set in any area d、the quantity of image charge is equal to the original charge of the system, and the sign is opposite to the original charge of the system
2、a right-hand circularly polarized wave normally incidents to a ideal conductor plate, the reflected wave is a、right-hand circularly polarized wave b、linear polarized wave c、left-hand circularly polarized wave d、left-hand elliptically polarized wave
3、the gps system employs the linear polarized em wave.
4、for electromagnetic waves of any frequency, sea water can be regarded as a good conductor.