Networks Analysis and Synthesis - Engineering

Q1:

A conductor has a cylindrical shape with a diameter d. Its resistance is 2 Ω. It is recast into a cylindrical conductor of diameter 0.3d. The resistance of new conductor is likely to be

A less than 2 Ω

B less than 0.6 Ω

C between 2 and 100 Ω

D more than 100 Ω

ANS:D - more than 100 Ω

Since new diameter is 0.3 d, the new area of cross-section a (0.3 d)2. The volume remains the same. Therefore length increase by a factor . Hence .