Electronics Engineering - Online Test
Q1. For the Zener diode shown in the figure, the Zener voltage at knee is 7 V, the
knee current is negligible and the Zener dynamic resistance is 10 Ω. If the input
voltage (Vi) range is from 10 to 16 V, the output voltage (V0) ranges from
Answer : Option C
Explaination / Solution:
Q2. Step responses of a set of three second-order underdamped systems all have the same percentage overshoot. Which of the following diagrams represents the poles of the three systems ?
Answer : Option C
Explaination / Solution:
Transfer function for the given pole zero plot is:
From the plot Re (P1 and P2)>(Z1 and Z2)
So, these are two lead compensator.
Hence both high pass filters and the system is high pass filter
Q3. Consider a system whose input x and output y are related by the equation 
where h(t) is shown in the graph.
Which of the following four properties are possessed by the system ?
BIBO : Bounded input gives a bounded output.
Causal : The system is causal,
LP : The system is low pass.
LTI : The system is linear and time-invariant.
where h(t) is shown in the graph.Which of the following four properties are possessed by the system ?
BIBO : Bounded input gives a bounded output.
Causal : The system is causal,
LP : The system is low pass.
LTI : The system is linear and time-invariant.
Answer : Option B
Explaination / Solution:
Here h(t) ! 0 for t < 0. Thus system is non causal. Again any bounded input x(t) gives bounded output y(t). Thus it is BIBO stable.
Q4. A certain system has transfer function 
where α is a parameter. Consider the standard negative unity feedback
configuration as shown below
where α is a parameter. Consider the standard negative unity feedback
configuration as shown belowWhich of the following statements is true?
Answer : Option C
Explaination / Solution:
Q5. A silicon PN junction is forward biased with a constant current at room temperature. When the temperature is increased by 10ºC, the forward bias voltage across the PN junction
Answer : Option D
Explaination / Solution:
For every 1º C increase in temperature, forward bias voltage across diode decreases by 2.5 mV. Thus for 10º C increase, there us 25 mV decreases
Q6. 
Assuming that the flip-flop are in reset condition initially, the count sequence observed at QA, in the circuit shown is
Answer : Option D
Explaination / Solution:
Q7. In the following graph, the number of trees (P) and the number of cut-set (Q) are
Answer : Option C
Explaination / Solution:
Q8. A linear, time - invariant, causal continuous time system has a rational transfer function with simple poles at s =- 2 and s =- 4 and one simple zero at s =- 1 . A unit step u(t) is applied at the input of the system. At steady state, the output has constant value of 1. The impulse response of this system is
Answer : Option C
Explaination / Solution:
Q9. The number of open right half plane of 
is
is
Answer : Option C
Explaination / Solution:
Q10. For a parallel plate transmission line, let v be the speed of propagation and Z be the characteristic impedance. Neglecting fringe effects, a reduction of the spacing between the plates by a factor of two results in
Answer : Option B
Explaination / Solution:
No Explaination.
