I need some help with these question:
Two long, straight wires are oriented perpendicular to the computer screen, as shown below, in which L = 4.5 cm. The current in one wire is I1 = 3.1 A, pointing into the screen, and the current in the other wire is I2 = 4.0 A, pointing out of the screen. Find the magnitude and direction of the net magnetic field at point P.
(see attachment for diagram)

A spherically symmetric volume charge distribution is given by
Rho® = k*r for r (less than or equal to) a
0 for r > a
Find:
a) what is the electric field both inside and outside the sphere
b) what is the potential at any point inside the sphere
c) How much energy was required to

1. how would you find the centre of mass of an irregularly shaped object which has an irregular mass distribution? Is it possible for the center of mass to be outside the object? Give an example.
2. describe the origins of magnetism at the atomic level and explain how it is possible for this atomic property to be detected on th

The electric field is defined as the electrostatic force divided by the charge experiencing this force. The Earth's electric field is directed radially inward and is about 150 N/C at the Earth's surface. This arises because in a region of the atmosphere known as the ionosphere, parts of the spectrum of the radiation from the sun

The magnetic field can store energy, but it can do no work. Therefore, another agency must be responsible for doing the work that puts the energy into the magnetic field. In order for the energy in the field to be reduced to zero, work must be done. Explain where the energy goes when the B field collapses. What possible agen

Two wires, each having a weight per unit length of 10^-4 N/m, are strung parallel, one 0.1 m above the other. If the wires carry the same current, through in opposite directions, how great must the current in each wire be for the magnetic field of the lower conductor to balance the weight of the upper conductor?

A straight wire along the z axis carries a charge density lamda traveling in the +z direction at speed v.
Construct the field tensor at the point (x,0,0)
Explain why the electric field has to be (2*lamda)/(4*pi*epsilon*x)
Explain what will happen if the problem changes to (y,0,0) for example.

Solid insulation sphere of non-uniform charge density. Finding the electric field in side the sphere using Gauss' law:
(a) Consider a solid insulating sphere of radius b with non-uniform charge density
s= ar, where 'a' is a constant. Find the charge Q_r contained within the radius r, when
r < b.
(b) If a = 2 x 10^-6 C

2. (a) (i) Write down Maxwell's equations for static electricand magnetic ﬁelds in the vacuum (note that you should include charge andcurrent densities).
(ii) How did Maxwell modify Ampére's law to account for dynamic electric ﬁelds?
(b) In a region of space in which the relative permittivity is (attached equation),

If a proton moved from 0 V potential to 10 V potential, would its potential energy increase or decrease? If an electron moved from 0 V potential to 10 V potential,would its potential energy increase or decrease? Explain.