Electrical Engineering - Online Test
Q1. Thyristor T in the figure below is initially off and is triggered with a single pulse of
width 10µs . It is given that 
Assuming latching
and holding currents of the thyristor are both zero and the initial charge on C is
zero, T conducts for
Assuming latching
and holding currents of the thyristor are both zero and the initial charge on C is
zero, T conducts for
Answer : Option C
Explaination / Solution:
No Explaination.
Q2. The Maxwell’s bridge shown in the figure is at balance. The parameters of the inductive coil are
Answer : Option A
Explaination / Solution:
No Explaination.
Q3. The open-loop transfer function of a dc motor is given as 
When connected in
feedback as shown below, the approximate value of Ka that will reduce the time constant of the
closed loop system by one hundred times as compared to that of the open-loop system is
When connected in
feedback as shown below, the approximate value of Ka that will reduce the time constant of the
closed loop system by one hundred times as compared to that of the open-loop system is
Answer : Option C
Explaination / Solution:
No Explaination.
Q4. Maximum of the real valued function f(x) = (x – 1)2/3 occurs at x equal to
Answer : Option C
Explaination / Solution:
Q5. Consider an LTI system with impulse response 
If the output of the system is 
then the input, x(t), is given by
If the output of the system is then the input, x(t), is given by
Answer : Option B
Explaination / Solution:
Q6. Shunt reactors are sometimes used in high voltage transmission system to
Answer : Option C
Explaination / Solution:
No Explaination.
Q7. 
A three-phase slip-ring induction motor, provided with a commutator winding, is shown in the figure. The motor rotates in clockwise direction when the rotor windings are closed.
If the rotor winding is open circuited and the system is made to run at rotational speed fr with
the help of prime-mover in anti-clockwise direction, then the frequency of voltage across slip
rings is f1 and frequency of voltage across commutator brushes is f2. The values of f1 and f2
respectively are
Answer : Option A
Explaination / Solution:
Q8. The current state QAQB of a two JK flip-flop system is 00. Assume that the clock rise-time is much
smaller than the delay of the JK flip-flop. The next state of the system is
Answer : Option C
Explaination / Solution:
Q9. In the Digital-to-Analog converter circuit shown in the figure below, VR = 1V and R = 1kΩ
The voltage V is
Answer : Option C
Explaination / Solution:
No Explaination.
Q10. Let ⊕ denote the Exclusive OR (XOR) operation. Let ‘1’ and ‘0’ denote the binary
constants. Consider the following Boolean expression for F over two variables P and Q.
F(P,Q) = ((1⊕P)⊕(P⊕Q))⊕((P⊕Q)⊕(Q⊕0))
The equivalent expression for F is
Answer : Option D
Explaination / Solution:
