Answers

2015-12-11T01:21:14+05:30

This Is a Certified Answer

×
Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
a)
A
a
a
A
Electric Resistance is the chracteristic property of a material which opposed the flow of electric current. It is denoted by "R" and its SI unit is ohm (Ω)

B
 Let
 new length,
new Area
 and
new resistance be
respectively :
 l' ,
 A'
and
 R' 


Given, l' = 2l and A' = A/2 

Since R = ρ l / A


So, R' = ρ * 2l / (A/2) = ρ * 4 l / A = 4 * (ρ l / A ) 
Since,
 R = ρ *l/A ,
So :
 R' = 4 * R

Resistivity depends on
the nature of material
not on the length/temperature or Area of cross-section.
So,
resistivity will remain CONSTANT
0