JEE Main202228 Jul 2022Morning ShiftPhysicsAlternating CurrentActual
The equation of current in a purely inductive circuit is 5 sin 49 π t - 30 ° . If the inductance is 30 mH then the equation for the voltage across the inductor, will be
Options
- A1 . 47 sin 49 π t - 30 °
- B1 . 47 sin 49 π t + 60 °
- C23 . 1 sin 49 π t - 30 °
- D23 . 1 sin 49 π t + 60 °
Correct answer
D. 23 . 1 sin 49 π t + 60 °
Step-by-step solution
In inductive circuit, the voltage leads the current by 90 ° . Therefore, ϕ 0 V - ϕ 0 I = 90 ° ⇒ ϕ 0 V = 60 ° From the given equation 5 sin 49 π t - 30 ° , angular frequency ω = 49 π   rad   s - 1 The amplitude of the voltage across the inductor will be, V 0 = i 0 X L ⇒ V 0 = i 0 ω L ⇒ V 0 = 5 49 π 30 × 10 - 3 = 23 . 1 ⇒ V = 23 . 1 sin 49 π t + 60 °