Finding the conduction current density - Physics Forums
2021年1月5日 · What is conduction current density? Conduction current density is a measure of the flow of electric charge through a material. It is typically represented by the symbol J and is measured in units of amperes per square meter. How is conduction current density calculated? Conduction current density can be calculated by dividing the current (I) by ...
How Do You Calculate Current Density in a Wire? - Physics Forums
2011年2月14日 · The current density can then be calculated using the formula J = I/A, where I is the current and A is the cross-sectional area of the wire. Why is current density important in electrical circuits? Current density is important in electrical circuits because it can help determine the efficiency and safety of the circuit.
How Is J₀ Calculated in a Wire with Nonuniform Current Density?
2008年4月13日 · In this case, we are dealing with a long, straight conducting wire with a nonuniform current density, meaning the current is not evenly distributed throughout the wire. To find an expression for J_{}0, we can use the formula for current density, J=I/A, where I is the total current and A is the cross-sectional area of the wire.
Finding current density given B-field - Physics Forums
2013年5月24日 · What is the formula for finding current density given the magnetic field? The formula for finding current density (J) given the magnetic field (B) is J = σB, where σ is the conductivity of the material. This formula is known as the Ohm's law for current density. Can current density be negative? Yes, current density can be negative.
Current density, drift velocity and electric field - Physics Forums
2012年4月29日 · In summary: You could also search online for this information. In summary, the conversation discusses the expression for current density and its units, deriving the expression in terms of microscopic quantities, and using the equations to solve for current density, average drift speed, and electric field strength in a copper wire.
Finding magnetic field in wire with non-uniform current density
2013年8月7日 · To find the magnetic field in a wire with non-uniform current density, you can use the formula B = μ0I/2πr, where B is the magnetic field, μ0 is the permeability of free space, I is the current, and r is the distance from the wire.
Finding diameter of a wire based on the current and current density.
2006年10月17日 · FAQ: Finding diameter of a wire based on the current and current density. What is the formula for finding the diameter of a wire based on current and current density? The formula for finding the diameter of a wire based on current and current density is: d = 2 * (I / J)^0.5, where d is the diameter, I is the current, and J is the current density.
K, the idealized surface current density - Physics Forums
2005年7月7日 · In summary, K refers to the surface current density, which is defined as the current per unit width-perpendicular-to-flow. It is related to the mobile surface charge density and velocity. The integral form of K can be written as I_surface = ∫K·dl, where ∫ …
Derivation of Fowler-Nordheim current density - Physics Forums
2004年10月20日 · Fowler-Nordheim current density is derived using the Fowler-Nordheim equation, which relates the current density to the electric field strength and the work function of the metal surface. This equation is based on the quantum mechanical tunneling effect. What factors affect the value of Fowler-Nordheim current density? The value of Fowler ...
How Is Current Density Calculated for Protons in the Solar Wind?
2008年3月18日 · In summary, the density of protons in the solar wind near Earth is 8.90 cm-3 with a speed of 490 km/s. To find the current density of these protons, the formula J = nqv is used, where n represents the number density of protons per unit of volume.