The mean free path of conduction electrons in copper is about `4 xx 10^(-8) m`. Find the electric field which can give 2 eV energy (on the average) to a conduction electron in a copper block.

The mean free path of electrons in a metal is 4xx10^-8m . eY energy to an electron in the metal will be

Estimate the average drift speed of conductin electrons in a copper wire of cross sectional area 1.0xx10^(-7) m^2 carrying a current of 1.5 A. Assume that each copper atom contributes roughly one conduction electron. The density of copper is 9.0xx10^3 kgm^(-3) and its atomic mass is 63.5 u.

The number density of electron in copper is 8.5 xx10^(28)m^(-3) . Find the current flowing through a copper wire of length 20 cm, area of cross section 1 mm square,when connected to a battery of 3 V. Given the electron mobility = 4.5xx10^(-6)m^(2)V^(-1) s^(-1) and electron charge = 1.6 xx 10^(-19)C.

Estimate the average drift speed of conductio electrons in a copper wire of cross-sectional area 10^-7m^2 carrying a current of 1.5 A, Assume the density of conduction electrosn to be 9xx10^28 m^-3 and change on electio = 1.6 xx10^-19 jC

A circular coil of 20 turns and radius 10 cm is placed in a uniform magnetic field of 0.10 T normal to the plane of the coil. If the current in the coil is 5.0 A, what is the average force on each electron in the coil due to the magnetic field? (The coil is made of copper wire of cross-sectional area 10^-5 m^2 , and the free electron density in copper is given to be about 10^29 m^-3 .)

The total energy of an electron in the first excited state of the hydrogen atom is about -3.4 eV. (A) What is the kinetic energy of the electron in this state? (B) What is the potential energy of the electron in this state? (C) Which of the answers above would change if the choice of the zero of potential energy is changed?

Two charges of +25 xx 10^-9 coulomb and -25 xx 10^-9 coulomb are placed 6 m apart. Find the electric field at a point 4 m from the centre of the electric dipole on axial line

The number density of free electrons in a metal piece is a very large of the order of 10^(+29) m^-3 . Why is there no current in the metal piece in the absence of electric field across it ?