Question

directly answer plz fast​

Answer 1

Rab is 5/4 ohm according my solution hope I am right and you understand my solution

Answer 2

Hey mate first of all your diagram is not correct . a rhombus cannot have it's diagonal equal to it's sides

still taking some liberty taking values as yours

Given resistivity of each side =0.2Ω cm

Hence if  rhombus is made up of same material

resistance of each side must be equal

$R_{AB}=R_{BC}=R_{CD}=R_{DA}$

$R=\rho \frac{l}{A} \\R=0.2\times \frac{10}{A} \\R=\frac{2}{A}$

Assuming wire to be of negligible thickness

$R=2ohm$

refer the attachment

hence now you can easily calculate the equivalent resistance

as the resistance in between get wasted hence resistances left are p,q,r and s

using these you can easily calculate the answer

as P and R are in series also Q and S are in series

along with them

the resultant of Pand R =PR

and resultant of Q and S =QS

PR and QS are in parallel

from the 2nd attachment it is clear that a wheatstone bridge is formed

and we know that if

p/q=r/s

the resistance in between get wasted or short circuited

hence you get your answer as

R_{AB}=2Ω

if the answer is wrong please refer your book for to check the figure an values  also check if the radius of wire is given