Find out the relation between `R_1, R_2, R_3 and R_4`.so there is no that current in R.

Explanation

`Delta T= T_1-T_2`
`T_1-T-i_1 R_1" "…(i)`
`T_1-T=i_2 R_3" "…(ii)`
Eq. (i) (ii)
`rArr (i_1 R_1)/(r_2 R_3)=1" "…(iii)`
`T-T_2=i_1 R_2" "…(iv)`
`T-T_2=i_2 R_4" "…(v)`
Eq. (4)/eq. (5)
`i_1 R_2=i_2 R_4" "...(iv)`
Eq. (iii)/(iv)
`(R_1)/(R_2)=(R_3)/(R_4)`
`rArr R_1 R_4=R_2 R_3`