Match List-I with List-II
|
List-I Formula |
List-II Physical quantity |
|
(A) $neAV_d$ |
(I) Mobility |
|
(B) $\frac{v_d}{E}$ |
(II) Current |
|
(C) $\frac{ne^2τ}{m}$ |
(III) Conductivity |
|
(D) $\frac{m}{ne^2τ}$ |
(IV) Resistivity |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (A)-(II), (B)-(I), (C)-(III), (D)-(IV)
|
List-I Formula |
List-II Physical quantity |
|
(A) $neAV_d$ |
(II) Current |
|
(B) $\frac{v_d}{E}$ |
(I) Mobility |
|
(C) $\frac{ne^2τ}{m}$ |
(III) Conductivity |
|
(D) $\frac{m}{ne^2τ}$ |
(IV) Resistivity |
Given formulas and physical quantities:
(A) $I = ne A v_d$
- $n$ = number density of charge carriers
- $e$ = charge of electron
- $A$ = cross-sectional area
- $v_d$ = drift velocity
This formula gives the current in a conductor. → (II) Current
(B) $v_d / E$
- $v_d$ = drift velocity
- $E$ = applied electric field
Mobility $\mu$ is defined as the ratio of drift velocity to electric field: $\mu = v_d / E$. → (I) Mobility
(C) $ne^2 \tau / m$
- $n$ = charge carrier density
- $e$ = charge
- $\tau$ = relaxation time
- $m$ = mass of electron
Electrical conductivity $\sigma = ne^2 \tau / m$. → (III) Conductivity
(D) $m / ne^2 \tau$
- This is the reciprocal of conductivity, hence represents resistivity $\rho$. → (IV) Resistivity