Current Density

Average and instantaneous current | Drift velocity | Mobility| Current density | Ohm's experimental law | Ohm's Law from drift velocity | Temperature dependence of resistivity for conductors | semi comductors and super conductors | Temperature dependence of resistance

a. A steady current flows in a metallic conductor of non - uniform cross section. State which of the quantities i.e., current density, electric field, and drift velocity, current density, electric field, and drift velcoity remain constant? b. A steady current passes through a cylindrical conductor. Is there an electorn field inside the conductor?

A : When a steady current flows through a conductor of non - uniform cross-section , the current density , electric field and drift velcoity do not remain constant. R : For a constant current the current density electric field and drift velocity are inversely proportional to cross - sectional area.

Is current density a vector or a scalar quantity ? Deduce the relation between current density and potential difference across a current carrying conductor of length l, area of cross-section A, and number density of free electrons n. How does the current density, in a conductor vary with (a) increases in potential gradient ? (b) increase in temperature? ( c) increase in length? (d) increase in area of cross-section? (Assume that the other factors remain constant in each case).

Consider a current carrying wire (current I) in the shape of a circle. Note that as the current progresses along the wire, the direction of j (current density) changes in an exact manner, while the current I remain unaffected. The agent that is essentially responsible for is

Consider a current carrying wire (current I) in the shape of a circle. Note that as the current progresses along the wire, the direction of vecJ (current density) changes in an exact manner, while the current I remains unaffected. The agent that is essentially responsible for is

Electric current is passing through a solid conductor PQ from P to Q. The electric current densities at p and Q are in the ratio.

A set of equations involving electric and magnetic fields, and their sources, the charge and current densities are known as ______ equations.

Circular regiions (1) and (2) have current densities J and -J respectively, such that their region of intersection carries no current. Magnetic field in their region intersection is