question_answer

In a circuit the coil of a choke:          

A)  decreases the current                

B)  increases the current               

C)  has high resistance to DC circuit      

D)  no effect with the current           

Correct Answer: A

Solution :

                Choke coil is a high inductance coil made of thick insulated copper wire wound closely in a large number of turns over a soft-iron laminated core. Since, the wire is of copper and is thick, its resistance (R) is almost zero, but due to large number of turns and high permeability of iron core its inductance is quite high. The coil, therefore offers a large reactance and contributes to the impedance of the circuit. This reduces alternating current appreciably. Thus, current in an alternating circuit is reduced by means of a choke coil.