Question

4.
The resistance of a conductor is 27 R. If it is cut into three equal
connected in parallel, then its total resistance is
(A) 602
(B) 3:02
(C)
92
(D) 272​

Answer 1

Answer:

Problem is that ..i think all options you gave are incorrect because my. answer is 3 ohm

steps

let resistance of wire=27=Ra

now,

27=rho×l/A-------------(eq.1)

now as wire is cut into 3 equal parts , its value of rho and area of croSection will not change but L now will get reduced to 1/3L

on basis of above statement we cam say that:-

{R1=R2=R3=rho×L/3/Area cross section }

【note:-R1,R2,R3 are the new resistances whose length is one - third of of 27ohm resistance】

now, R1=( RHO×L/3/A)

=( Rho×L/3A)

=1/3(rho×L/A)

=1/3(27). {from eq.1}

R1=[9ohm]= R2 =R3

as they are connected in parallel

equivalent resistance=3ohm