Transients

Transient currents in electrical circuit are associated with

(a) inductors 

(b) capacitors 

(c) resisters 

(d) both (a) and (b).

The transient current in a loss-free L-C circuit when excited from an ac source is a/ an ….. sine wave. 

(a) over damped 

(b) undamped 

(c) under damped 

(d) critically damped.

The transients which are produced due to sudden but energetic changes from one steady state of a circuit to another are called ……. transients. 

(a) initiation 

(b) transition 

(c) relaxation 

(d) subsidence

Transient disturbance is produced in a circuit whenever 

(a) it is suddenly connected or disconnected from the supply 

(b) it is shorted 

(c) its applied voltage is changed suddenly 

(d) all of the above.

There are no transients in pure resistive circuits because they 

(a) offer high resistance 

(b) obey Ohm’s law 

(c) have no stored energy 

(d) are linear circuits.

Transient current in an R-L-C circuit is oscillatory when 

(a) R = 0 

(b) R  > 2√(L/C)

(c) R  < 2√(L/X)

(d) R = √(L/C) 

A circuit of resistance 10 Ω and inductance 0.1 H in series has a direct voltage of 200 V suddenly applied to it. Find the voltage drop across the inductance at the instant of switching on and at 0.01 second. Find also the flux-linkages at these instants.

A 50-Hz sinusoidal voltage of maximum value of 400 V is applied to a series circuit of resistance 10 Ω and inductance 0.1 H. Find tan expression for the value of the current at any instant after the voltage is applied, assuming that voltage is zero at the instant of application. Calculate its value 0.02 second after switching on

A 1.0 H choke has a resistance of 50 Ω . This choke is supplied with an a.c. voltage given by e = 141 sin 314 t. Find the expression for the transient component of the current flowing through the choke after the voltage is suddenly switched on.

Double-energy transients are produced in circuits consisting of 

(a) two or more resistors 

(b) resistance and inductance 

(c) resistance and capacitance 

(d) resistance, inductance and capacitance.