Question

2 wires of radius of cs r but of different material are connected together end to end.If the densities of charge carriers in the two wires are in ratio1:4 then ratio of drift velocity will be

Answer 1

✔️✔️Let drift velocities of the wires be vd and vd'


✔️✔️Area of cross- section of two wires be A and A'.

A : A' = 1:4
A' = 4A

⭕️When the two wires are connected in series, the same amount of current flows through both the wires.


⭕️n A vd e = n A' vd' e

✔️✔️n is the number of electrons per unit volume

✔️✔️e is the charge on electron.

⭕️vd=A'A =4A

A=4:1

✔️✔️remember :-

When the two wires are connected in parallel, the potential difference across the two wires would be the same.