Question

You are given several identical resisters each of value 5ohm
and each capable of carrying a maximum
current of 2A. It is required to make a suitable combination of these resistances to produce a resistance
of 2.5ohm which can carry current of 4A. The minimum number of resistances required for this job is​

Answer 1

Answer:

8

Explanation:

Here we need four parallel paths, each carrying a current of 1A. If R s the resistance of each path, then the equivalent resistance of the combination is  

R/4  

And as per given criteria,  

R/4 =5

4x5Ω⟹R=20Ω

Therefore, two resistors should be connected in each path , total number of resistors = 8