Q.

Column-I gives certain physical terms associated with flow of current through a metallic conductor. Column-II gives some mathematical relations involving electrical quantities. Match column-I and column-II with appropriate relations.                   [2021]

  Column-I   Column-II
(A) Drift velocity (P) mne2ρ
(B) Electrical Resistivity (Q) nevd
(C) Relaxation Period (R) eEmτ
(D) Current Density (S) EJ

 

1 (A)-(R), (B)-(Q), (C)-(S), (D)-(P)  
2 (A)-(R), (B)-(S), (C)-(P), (D)-(Q)  
3 (A)-(R), (B)-(S), (C)-(Q), (D)-(P)  
4 (A)-(R), (B)-(P), (C)-(S), (D)-(Q)  

Ans.

(2)

The formula of drift velocity is vd=eEmτ

Current density J=IA=neAvdA=nevd

Resistivity is ρ=mne2ττ=mne2ρ

Resistance is R=VI  ;  ρlA=ElIρ=EAI=EJ

where, E=electric field, A=area of cross section

e=electronic charge, n=number of density of electrons,

τ=relaxation time.