Spread the love

Mobility Class 12 Physics | Mobility

Mobility Class 12 Physics | Mobility :- Electrical conductivity of a material is due to moving charge carriers. In metals these mobile charge carriers are electrons, in ionized gases these are electrons and positively charged ions and in electrolytes they can be both positive and negative ions.

Mobility is defined as the magnitude of drift velocity per unit electric field.

$\displaystyle \mu =\frac{\left| {{v}_{d}} \right|}{E}$

SI Unit of Mobility

(Mobility Class 12 Physics)

SI unit :- m²/Vs

Practical Unit :- cm²/Vs

SI unit = 10⁴× (Practical Unit)

Now as $\displaystyle {{v}_{d}}=\frac{eE\tau }{m}$ (Drift Velocity)

Hence,

$\displaystyle \mu =\frac{{{v}_{d}}}{E}=\frac{e\tau }{m}$

where τ is the average relaxation time of the electrons.

Mobility Class 12 Physics | Mobility

SI Unit of Mobility

(Mobility Class 12 Physics)

Like this: