The electron drift speed is estimated to be only a few `mm.s^-1` for currents in the range of a few ampere.How then is current established almost the instant a circuit is closed?

IF the electron drift speed is so small and the electron's charge is also small,then how can we still obtain a large amount of current in a conductor?

When 5V potential difference is applied across a wire of length 0.1 m, the drift speed of electron a 2.5 times 10^-4 m.s^-1 . IF the electron density in the wire is 8 times 10^28 m^-3 , the resistivity of the material is close to

Estimate the average drift speed of conduction electrons in a copper wire of across sectional area 1.0 times 10^-7 m^2 carrying a current of 1.5A.Assume the density of conduction electrons to be 9 times 10^28 m^-3 .

A few storage cells in series are to be charged from a 200 V dc supply. The emf of each cell is 2.5 V, Internal resistance 0.1 Omega and the charging current is 8A. In this arrangement how many cells can be charged and what extra resistance is required to be conncted in the circuit?

Compare the drift speed obtained above with (a) thermal speed of electrons carrying the current at room temperature and (b) speed of propagation of electric field along the conductor which causes the drift motion.Avogadro's number= 6.0 times 10^26 per kg atom. Boltzmanm constant , k=1.38 times 10^-23 J.K^-1 mass of electron =9.1 times 10^-31 kg .

Estimate the average drift speed of conduction electrons in a copper wire of cross sectional area 1.0 times 10^-7 m^2 carrying a current of 1.5 A.Assume that the number density of conduction electrons is 9 times 10^25 m^-3 charge of an electron = -1.6 times 10^-19C .

A circular coil of radius 8.0 cm and 20 turns rotates about its vertical diameter with an angular speed of 50 rad. s^(-1) in a uniform horizontal magnetic field of magnitude 3.0xx10^(-2)T . Obtain the maximum and average emf induced in the coil. If the coil forms a closed loop of resistance 10 Omega , calculate the maximum value of current in the coil. Calculate the average power loss due to Joule heating. Where does this power come from?

When a current of 1 A flows through a copper wire of cross sectional area 1mm^2 the drift velocity of free electrons becomes v, What will be the drift velocity of free electrons when the same current flows through a copper wire of cross sectional area 2mm^2 ?

The number of free electrons per unit volume in a metallic conductor is 10^22 cm^-3 .The area of cross section of the conductor is 1mm^2 and the strength of current through the conductor is 1A. Determine the drift velocity of the free electrons,(Given that the charge of an electron -1.6 times 10^-19 C )

An electrical system has open-closed switches S_1, S_2 and S_3 as shown in fig. The switches operate independently of one another and the current will flow from AtoB either if S_1 is closed or if both S_2 and S_3 are closed. If P(S_1)=P(S_2)=P(S_3)=1//2, then find the probability that the circuit will work.