Saved Bookmarks
| 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)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 |
|