1.

A wire of 15Ω resistance is gradually stretched to double its original length. It is then cut into two equal parts. These parts are then connected in parallel across a 3.0volt battery. Find the current drawn from the battery.

Answer»

When length of a given wire is made n-times by strecting it, its resistance becomes n2 times

i.e., R' =n2R = (2)x 15 = 60Ω 

Resistance of each half part 60/2 = 30Ω

When both parts are connected in parallel, final resistance = 30/2 = 15Ω

Current drawn from battery,

I = V/R

= 3.0/15 = 0.2A



Discussion

No Comment Found

Related InterviewSolutions