Question

S.i unit of mobility is metre/ ampere ×second

Answer 1

SI unit of mobility is (m/s)/(V/m) = m2/(V. s). 

Answer 2

Mobility is the drift velocity of a charge carriers in a conductor on applying Unit Electric Field...

Mobilty
u = Vd(Drift velocity) as it is a velocity of charge particles in the conductor when electric is being applied...Drift motion is a uniform motion..so its unit will be m/s...
E = Electric Field which is a character of a space due to Source Charge which applies force when any other charge enter that space , it experience force...When an electri charge enter an E , it experiences force becuase of it starts accelerating along the direction of E...

The relation of E is as follows.. E= Electrostatic Force/Charge So unit will be Newton(N)/Coloumb(C)Or E = - Pottential Difference/Distance between the two potentials...Unit will be Volt(V)/meter(m)...

So unit of Mobilty..

mobilty, u = Vd / E ,

if unit of E = N/C then unit of u will be m/s / N/C
= meter x Coloumb / Newton x Second

if unit of E = V/m then unit of u will be m/s / V/m
= meter x meter / second x Volt
=meter square / Second x Volt...

If you want to write the unit of mobility with ampere...See first unit of Mobilty which is equal to
meter x Coloumb / Newton x Second...
This can also be written as..
meter/Newton x Coloumb/second
= meter/Newton × Ampere
= meter x Second / Newton..
hope this help..