Electricity and Magnetism Answers

A uniform current J1 = Jocoswtêy flow on the surface z =0,and a second sheet of current J2 = J0sinwtêy flows in the surface z = pic/2w where ey is the unit vector along y and Jo,w are constant.

 a) Find solution of Maxwell's equations that fit the boundary conditions with E= B=0 z<0

 b) Calculate the flux of the poynting vector field and compare it to average power per unit area that must be supplied to drive these currents.

find the ratio of the resistances of a copper wire to an aluminum wire if the length and diameter of the aluminum wire is twice the diameter of the copper

the resistance of a rod with a length of 3.0m and a diameter of 1.0cm is 56.0 ohms. of this rod is stretched to form a wire with a diameter of 0.01cm, what is its resistance? assume that in the process of stretching the rod, its volume did not change.

wires a and b are made for the same material and have the same length. however, the diameter of wire a is thrice the diameter of wire b. wire a has a resistance of 12.0 ohms. what is the resistance of wire b?

A linearly polarized wave with Ē in the xy plane is incident from x > 0 on an interface at x = 0. In the region x > 0 is free space and in the region x< 0 is a medium with dielectric constant e,

a) If the incidence angle is 45 degrees and angle of transmitted(refracted wave) is 90 degree find the dielectric constant ?

b)Find E and B for z>0 and calculate the time average of Poynting vector component along x (i.e. S_x) flowing through x = 0.

Find the electric field ⃗ (E)due to a disk above ‘z’ height from its centre which has a 

constant surface charge σ. Given that disk’s radius is ‘a’.

4.0 x 105 neutrons = _________________ C

what ia the net direction of net coulomb force on Q3 from + x axis? (answer in degree).

Q2 is 50cm to the right from Q1 and Q3 is 40cm below Q1.

Q1 = 35 x 10-6 C

Q2= 65 x 10-6 C

Q3 = 80 x 10-6 C

the net force on unknown charge is zero. what os distance between Q1 and Q2.

Distance between Q and Q1 is 50 cm, Q1 = 30×10-6 C and Q2 = 60×10-6 C.

One charge of 2.0C is 1.5m away from a -3.0e charge. Determine the force they exert from each other.