KVPY SX SB Exam 2016 Question Paper

Resultant of ${\mathit{V}}_{\mathit{C}},{\mathit{V}}_{\mathit{R}}$ & B give ${\mathit{V}}_{\mathit{i}}$ and angle between ${\mathit{V}}_{\mathit{i}}$ & B is ϕ. When f is very high ${\mathit{X}}_{\mathit{C}}\to \mathit{O}$ then ${\mathit{V}}_{\mathit{C}}\to \mathit{O}$
∴ Resultant of ${\mathit{V}}_{\mathit{C}},{\mathit{V}}_{\mathit{R}}$ & B lie between B and ${\mathit{V}}_{\mathit{R}}$.B lag behind ϕ
∴ At higher frequency ϕ become – ve.