Questions# $4$: Multiple Choice Questions: $($Marks $10)$

i$-$ If length of wire change, then resistivity may:

a$-$ Increase

c$-$Decrease

b$-$ Remain same

d$-$none of above

ii$-,$ In case of conventional current passing through wire, what is direction of J:

a$-$ In direction of positive charges

c $-$in direction of conventional current

b$-$ Both a and b

d$-$ None of above

iii$-$ In case of negative charge carrier, what is direction of $J$ and $vd$ :

a$-$ J and vd in same direction

$c-$ J has no effect on vd

b$-$ J and vd in opposite direction

$d-$ none

iv$-$ The unit of conductance is:

a$-$ Siemens

c$-$ ohm$-$m

b$-$ mho

$d-$a and $b$

v$-$ Resistivity depends on which factors

a$-$ dimensions

c$-$ material

b$-$ temperature

d$-$material and temperature