Question

Example 12.6
Awire of given material having length land area of cross-section A
has a resistance of 4 12. What would be the resistance of another wire
of the same material having length 1/2 and area of cross-section 2A?​

Answer 1

Answer:

l1= l

a1=a

r1= 412

rho1=rho2

l2=1/2

a2=2a

let r2 be x

r1=l1/a1

412= l /a

now

r2=l2/a2

r2=1/2l/2a

r2 = 1/4 ×l/a

and l/a= 412

so r2=1/4×412

r2=103