Question

A straight conductor of uniform cross-section carries a current I. If s is the specific charge of an electron, the momentum of all the free electrons per unit length of the conductor, due to their drift velocity only is –

• A. Is
• B.
• C. I/s
• D. (I/s)²

Answer 1

Answer: (C)

I/s

Answer 2

$\frac { \text { momentum of allfreee } ^ { - } } { \text {length } }$ = $\frac { \left( \mathrm { mv } _ { \mathrm { d } } \right) ( \mathrm { n } \times \text { volume } ) } { \ell }$

= mv_dn A I = neAv_d

= m = $\frac { \mathrm { I } } { \mathrm { S } }$ s = e/m