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JEE Advanced2011PhysicsAlternating CurrentActual

A series R-C combination is connected to an AC voltage of angular frequency =500 rad / s . If the impedance of the R-C circuit is R 1.25 , the time constant (in millisecond) of the circuit is

Correct answer

4

Step-by-step solution

Z= R^2+X_C^2 =R 1.25 R^2+X_C^2=1.25 R^2 or X_C= R 2 or 1 C = R 2 aligned Time constant & =C R= 2 & = 2 500 ~s =4 ~ms aligned Answer is 4 . Analysis of Question (i) Question is very simple. (ii) I think this is one of the simplest formula based question of this paper.

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