Networks Analysis and Synthesis - Engineering

Q1:

A wire has a diameter d and resistance R. If the diameter is made 3d, the length and material remaining the same, the new value of resistance will be

A R/3

B 3 R

C R/9

D 9 R

ANS:C - R/9

Since diameter is 3d, area of cross-section is increased 9 times. Therefore, resistance is R/9.