The magnetic field can be calculated using the formula B = μ0(I/2πr), where B is the magnetic field strength, μ0 is the permeability of free space, I is the current, and r is the distance from the current. This formula applies to a straight current-carrying wire. For other configurations, such as a loop or a solenoid, different formulas may be used.
The electric field can be calculated using the formula E = k(Q/r^2), where E is the electric field strength, k is the Coulomb's constant, Q is the charge, and r is the distance from the charge. This formula applies to a point charge. For other configurations, such as a line of charge or a charged disk, different formulas may be used.
To calculate the magnetic field at a point due to multiple current-carrying wires, you can use the principle of superposition. This means that you can calculate the magnetic field at the point due to each wire individually, and then add them together to get the total magnetic field. The formula for each individual magnetic field is the same as for a single wire (B = μ0(I/2πr)), but you must take into account the direction and magnitude of each wire's current.
No, the electric field inside a conductor is always zero. This is because in a conductor, the free charges (such as electrons) are able to move freely, and any electric field would cause them to move until they reach equilibrium. Therefore, the electric field inside a conductor must be zero in order for there to be no net motion of charges.
The magnetic field inside a solenoid can be calculated using the formula B = μ0nI, where B is the magnetic field strength, μ0 is the permeability of free space, n is the number of turns per unit length, and I is the current. This formula only applies to an ideal solenoid with an infinite length and tightly wound coils. For real solenoids, the magnetic field can be calculated using the principle of superposition, taking into account the magnetic field contributions from each individual turn of the coil.