Curioustab

Home » Electronics and Communication Engineering » Materials and Components

A specimen of metal has n valence electrons per m3. If vx is the average velocity of these electrons, each having a charge e, the current density J is

J = ne vx
J = - ne vx
J =
J =

Correct Answer: J = - ne vx

← Previous Question Next Question→

More Questions from Materials and Components

A metal has a large number of free electrons. If e is electronic charge and m is mass of electron and an electric field E is applied along (say) x direction, the electrons acquire a velocity having a component vx is x direction. Then
If the operating temperature increases by 10°C, the rate of deterioration of solid dielectric becomes
The measurement of Hall coefficient of a semiconductor with one type of charge carriers gives the information about
When two conductors carry currents in the same direction the force is repulsive.
When a trivalent impurity is added, the semiconductor becomes
For dielectrics in alternating field, polarizability ae is a complex quantity. The imaginary part of ae is zero for
Bitter powder patterns prove the existence of domains.
Assertion (A): If an electron having charge e is revolving in an orbit of radius R and with angular velocity ω, the magnetic dipole moment of orbit is 0.5 eωR2. Reason (R): Orbital angular momentum and magnetic dipole moment are always equal.
For making a capacitor it is better to have a dielectric having
Assertion (A): The angular momentum of an atom is due to three contributions viz. orbital, electron spin and nuclear spin. Reason (R): The nuclear spin magnetic moment is much more than electron spin magnetic moment.

Discussion & Comments

No comments yet. Be the first to comment!

Join Discussion