The power factor of an R-L circuit is 1 2 . If the frequency of AC is doubled the power factor will now be

Step-by-step solution

The power factor of an R-L circuit is given as, aligned & = R R ^2+ X _ L ^2 & R R ^2+ X _ L ^2 = 1 2 & 1 1+ ( X _ L R )^2 = 1 2 & 1 1+ ( L R )^2 = 1 2 & ( L R )^2+1=2 & L R =1 aligned So, when the AC frequency is doubled, aligned L R & =2 & = 1 1+ ( L R )^2 = 1 1+(2)^2 & = 1 5 aligned