Two rods are joined to end, as shown. Both have a cross sectional area of 0.01 cm ^2 . Each is 1 meter long. One rod is of copper with a resistivity of 17 10⁻⁶ ohm-centimeter, the other is of iron with a resistivity of 10⁻⁵ ohm centimeter. How much voltage is required to produce a current of 1 ampere in the rods?

Step-by-step solution

According to the question Length of each rod l=1 ~m Area of cross-section of cach rod A =0.01 ~cm ^2=0.01 10⁻⁴ ~m ^2 If _ c u = resistivity of copper and _ C W is resistivity of iron then aligned & _ c u =1.7 10⁻⁶ cm =1.7 10⁻⁸ & _ f e =10⁻⁵ cm =10⁻⁷ aligned New Resistance of Cu rod = R _ c u = aligned & _ c u 1 ~A & and Resistance of iron rod & _ f e = _ f e 1 ~A aligned Both are connected in series then equivalent resistance is aligned R_ e s =R_ c e +R_ F e & = _ c u l ~A + _ f e l ~A = l ~A ( _ c u + _ f e ) & V