 ## Friday, February 15, 2019

### Electric Circuit Theory (Objective Questions With Answers)

 The period of the signal x(t) = 8 sin (0.8πt + π /4) is [GATE 2010]
A. 0.4πs
B. 0.8πs
C. 1.25s
D. 2.5s

 The switch in the circuit has been closed for a long time. It is opened at t=0. At t=0+,the current through the 1μF capacitor is [GATE 2010]
A. 0A
B. 1A
C. 1.25A
D. 5A

 The second harmonic component of the periodic waveform given in the figure has an amplitude of [GATE 2010]
A. 0
B. 1
C. 2/π
D. √5
 As shown in the figure, a 1 resistance is connected across a source that has a load line v+i=100. The current through the resistance is [GATE 2010]
A. 25A
B. 50A
C. 100A
D. 200A

 If the 12Ω resistor draws a current of 1A as shown in the figure, the value of resistance R is [GATE 2010]
A. 4Ω
B. 6Ω
C. 8Ω
D. 18Ω

 If the electrical circuit of figure (b) is an eqiuvalent of the coupled tank system of figure (a), then [GATE 2010]
A. A,B are resistances and C,D capacitances
B. A,C are resistances and B,D capacitances
C. A,B are capacitances and C,D resistances
D. A,C are capacitances are and B,D resistances

 The two-port network P shown in the figure has ports 1 and 2, denoted by terminals (a,b) and (c,d), respectively. It has an impedence matrix Z with parameters denoted by Zij. A 1Ω resistor is connected in series with the network at port 1 as shown in the figure. The impedance matrix of the modified two-port network (shown as a dashed box) is [GATE 2010]
Ans:C

 The Maxwell's bridge shown in the figure is at balance.The parameters of the inductive coil are [GATE 2010]
A. R=R2R3/R4, L=C4R2R3
B. L=R2R3/R4, R=C4R2R3
C. R=R4/R2R3, L=1(C4R2R3)
D. L=R4/R2R3, R=1/(C4R2R3)

: The initial current through the inductor is zero, while the initial capacitor voltage is 100V. The switch is closed at t=0. The current i through the circuit is: [GATE 2010]
A. 5cos(5x103t)A
B. 5sin(104t)A
C. 10cos(5x103t)A
D. 10sin(104t)A

: The L-C circuit of statement is used to commutate a thyristor, which is initially carrying a current of 5A as shown in the figure below. The values and initial conditions of L and C are the same as in statement. The switch is closed at t=0. If the forward drop is negligible, the time taken for the device to turn off is [GATE 2010]
A. 52μs
B. 156μs
C. 312μs
D. 26μs