Tag: electric current, potential difference and resistance

There is a current of 40 amperes in a wire of $10^{-16}m^{2}$ area of cross-section. If the number of free electrons per $m^{3}$ is $10^{29}$, then the drift velocity will be:

A potential difference $V$ is applied to a copper wire of length $l$ and thickness $d$. If $V$ is doubled, the drift velocity:

The number of free electrons per $10$ mm ordinary copper wire is about $2\times 10^{21}$. The average drift speed of the electrons is $0.25$ mm current flowing is:

There is current of 40 amperes in a wire of $10^{-6}m^{2}$ area of cross -section. If the number of free electrons per $m^{3}$ is $10^{29}$, then the drift velocity will be 

Drift speed of conduction electrons in the wire is

In a wire of cross section radius r, free electrons travel with drift velocity V when a current a $I$ flows throught the wire. What is the current in another wire of half the radius and of the same material when the drift velocity is $2V$ ?

The mean free path of electrons in a metal is $44 \times 10 ^ { - 8 } \mathrm { m }$ . Theelectric field which can give on an average 2$e \mathrm { V }$ energy to an electron in the metal will be in units of VIm 

When 3 V potential difference is applied a wire of length 0.1 m. having resistivity $1.6 \times 10^{-5}$ $\Omega m$, the electrons started moving. If the electron density in the wire is $6 \times 10^{10} m^{-1}$, the drift speed of electrons is  

The drift velocity of free electron in a metal wire of a given potential gradient along it is $ V _d $ if this potential gradient is doubled the new drift velocity will be 

When a potential difference $V $  is applied across a conductor at a temperature $T,$  the drift velocity of electrons is proportional to