Electrical Engineering - Online Test
Q1. 
For the operational amplifier circuit shown, the output saturation voltages are ± 15V. The upper and lower threshold voltages for the circuit are, respectively.
Answer : Option B
Explaination / Solution:
Q2. We have a set of 3 linear equations in 3 unknowns.
means X and Y are
equivalent statements and 
means X and Y are not equivalent statements.
means X and Y are
equivalent statements and means X and Y are not equivalent statements. P: There is a unique solution.
Q: The equations are linearly independent.
R: All eigenvalues of the coefficient matrix are nonzero.
S: The determinant of the coefficient matrix is nonzero.
Which one of the following is TRUE?
Answer : Option A
Explaination / Solution:
No Explaination.
Q3. Two coins R and S are tossed. The 4 joint events HRHS,
TR TS,HR TS,TR HS have
probabilities 0.28, 0.18, 0.30, 0.24, respectively, where H represents head and T
represents tail. Which one of the following is TRUE?
Answer : Option D
Explaination / Solution:
Q4. The phase cross-over frequency of the transfer function 
is
is
Answer : Option A
Explaination / Solution:
Q5. 
The circuit shown in the figure has an ideal opamp. The oscillation frequency and the condition to sustain the oscillations, respectively, are
Answer : Option D
Explaination / Solution:
By virtual ground property, we write
We equate imaginary part to zero, i.e.
The condition to sustain the oscillation is
Q6. A vector 
is given by 
Which one of the following statements is TRUE?
is given by Which one of the following statements is TRUE?
Answer : Option A
Explaination / Solution:
Given vector,
If divergence 
then vector 
is solenoidal. So, we obtain
then vector is solenoidal. So, we obtainHence, it is solenoidal.
Again, if curl 
then 
is irrotational. So, we obtain
then is irrotational. So, we obtain
Q7. Consider a causal LTI system characterized by differential equation 
The response of the system to the input 
where u(t) denotes the unit step
function, is
The response of the system to the input where u(t) denotes the unit step
function, is
Answer : Option D
Explaination / Solution:
Q8. The inductance and capacitance of a 400 kV, three-phase, 50 Hz lossless transmission line are 1.6 mH/km/phase and 10 nF/km/phase respectively. The sending end voltage is maintained at 400 kV. To maintain a voltage of 400 kV at the receiving end, when the line is delivering 300 MW load, the shunt compensation required is
Answer : Option B
Explaination / Solution:
Q9. Three single-phase transformers are connected to form a delta-star three-phase transformer of 110 kV/ 11 kV. The transformer supplies at 11 kV a load of 8 MW at 0.8 p.f. lagging to a nearby plant. Neglect the transformer losses. The ratio of phase currents in delta side to star side is
Answer : Option A
Explaination / Solution:
Q10. Four messages band limited to W,W,2W and 3W respectively are to be multiplexed using Time Division Multiplexing (TDM). The minimum bandwidth required for transmission of this TDM signal is
Answer : Option D
Explaination / Solution:
Bandwidth of TDM is
= 1/2 (sum of Nyquist Rate)
= 1/2 [2W + 2W + 4W + 6W] = 7W
