Electrical Engineering - Online Test
Q1. For the following feedback system 
The 2% settling time of the
step response is required to be less than 2 seconds.
The 2% settling time of the
step response is required to be less than 2 seconds.
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. In the circuit shown below, the current I is equal to
Answer : Option B
Explaination / Solution:
From star delta conversion we have
Replacing in circuit we have the circuit shown below :
Now the total impedance of circuit is
Q3. A fair coin is tossed independently four times. The probability of the event “the number of time heads shown up is more than the number of times tail shown up”
Answer : Option D
Explaination / Solution:
No Explaination.
Q4. The first six points of the 8-point DFT of a real valued sequence are 5, 1 - j3, 0, 3 - 4j, 0 and 3 + 4j .....The last two points of the DFT are respectively
Answer : Option B
Explaination / Solution:
For 8 point DFT, 
and it is conjugate
symmetric about x[4], x[6] = 0; x[7] = 1 + j3
and it is conjugate
symmetric about x[4], x[6] = 0; x[7] = 1 + j3
Q5. 
The Nyquist plot of a stable transfer function G(s) is shown in the figure are interested in the stability of the closed loop system in the feedback configuration shown.
Which of the following statements is true ?
Answer : Option B
Explaination / Solution:
The plot has one encirclement of origin in clockwise direction. Thus G(s) has a zero is in RHP.
Q6. If 
over the path shown in the figure is
over the path shown in the figure is
Answer : Option C
Explaination / Solution:
Q7. In the circuit shown below, the initial charge on the capacitor is 2.5 mC, with
the voltage polarity as indicated. The switch is closed at time t = 0. The current i(t) at a time t after the switch is closed is
Answer : Option A
Explaination / Solution:
Here we take the current flow direction as positive.
Q8. The output of the combinational circuit given below is
Answer : Option C
Explaination / Solution:
Q9. 
The Nyquist plot of a stable transfer function G(s) is shown in the figure are interested in the stability of the closed loop system in the feedback configuration shown.
The gain and phase margins of G(s) for closed loop stability are
Answer : Option C
Explaination / Solution:
The Nyzuist plot intersect the real axis ate - 0.5. Thus
G. M. =- 20 log x =- 20 log 0.5 = 6.020 dB
And its phase margin is 90◦c
Q10.
Consider differential equation with 
the initial condition y(0) = 0. Using Euler’s first order method with a step size of 0.1, the value of y(0.3) is
the initial condition y(0) = 0. Using Euler’s first order method with a step size of 0.1, the value of y(0.3) is
Answer : Option B
Explaination / Solution:
Taking step size h = 0.1, y(0) = 0
From table, at x = 0.3,y(x = 0.3) = 0.031
