Electrical Engineering - Online Test
Q1. In the circuit shown, the device connected Y5 can have address in the range
Answer : Option B
Explaination / Solution:
Q2. If E denotes expectation, the variance of a random variable X is given by
Answer : Option A
Explaination / Solution:
The variance of a random variable x is given by
E X − E X
Q3. In the ac network shown in the figure, the phasor voltage VA (in Volts) is
Answer : Option D
Explaination / Solution:
Q4. 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:
Q5. 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
Q6. 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.
Q7. 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:
Q8. 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
Q9. 
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:
Q10. The following plot shows a function which varies linearly with x . The value of
the integral 
is
is
Answer : Option B
Explaination / Solution:
The given plot is straight line whose equation is
