What should be the length of a nichrome wire of resistance `4.5 Omega`, if the length of a similar wire is `60 cm` and resistance `2.5 Omega` ?

Answer

108 cm

Explanation

As `R prop l , (R_1)/(R_2)= (l_1)/(l_2)` or `(4.5 Omega)/(2.5 Omega) = (l_1)/(60 cm)` or `l_1 = (60 cm)((4.5 Omega)/(2.5 Omega))= 108 cm`.