Electrical Engineering - Online Test
Q1. A transmission line of characteristic impedance 50Ω is terminated by a 50 W load. When excited by a sinusoidal voltage source at 10 GHz, the phase difference between two points spaced 2 mm apart on the line is found to be π/4 radians. The phase velocity of the wave along the line is
Answer : Option C
Explaination / Solution:
We have d = 2 mm and f = 10 GHz
Q2. 
In the following transistor circuit, 
, and 𝛽 and all the capacitances are very large
, and 𝛽 and all the capacitances are very largeThe value of DC current IE is
Answer : Option A
Explaination / Solution:
For the given DC values the Thevenin equivalent circuit is as follows
Q3. A system with transfer function 
has an output
for the input signal 
Then, the system parameter p is
has an output for the input signal Then, the system parameter p is
Answer : Option B
Explaination / Solution:
Transfer function is given as
Amplitude Response
Alternative :
Q4. A small percentage of impurity is added to an intrinsic semiconductor at 300 K. Which one of
the following statements is true for the energy band diagram shown in the following figure?
Answer : Option A
Explaination / Solution:
New energy level is near to conduction band, so it is pentavalent atoms to form n-type semiconductor.
Q5. The equation x − x + x − = is to be solved using the Newton - Raphson method. If x = is taken as the initial approximation of the solution, then next approximation using this method will be
Answer : Option B
Explaination / Solution:
Q6.
Which one of the following gives the simplified sum of products expression for the Boolean function F =
m0 + m2 + m3 + m5, where m0,
m2, m3
and m5 are minterms corresponding to the inputs A, B and C with A as the MSB and C as the LSB?
and m5 are minterms corresponding to the inputs A, B and C with A as the MSB and C as the LSB?
Answer : Option B
Explaination / Solution:
F =
m0 + m2 + m3 + m5, ⟶ minterm
Q7. In an 8085 microprocessor, the shift registers which store the result of an addition and the overflow bit are, respectively
Answer : Option B
Explaination / Solution:
The shift registers A and F store the result of an addition and the overflow bit.
Q8. The modes in a rectangular waveguide are denoted by 
where
m n and are the eigen numbers along the larger and smaller dimensions of the
waveguide respectively. Which one of the following statements is TRUE?
where
m n and are the eigen numbers along the larger and smaller dimensions of the
waveguide respectively. Which one of the following statements is TRUE?
Answer : Option A
Explaination / Solution:
TM11 is the lowest order mode of all the TMmn modes
Q9. The impulse response h(t) of linear time - invariant continuous time system is given by h(t) = exp(- 2t)u(t), where u(t) denotes the unit step function.
The output of this system, to the sinusoidal input x(t) = 2 cos 2t for all time t , is
Answer : Option D
Explaination / Solution:
Q10. 
For the two-port network shown below, the short-circuit admittance parameter matrix is
Answer : Option A
Explaination / Solution:
Given circuit is as shown below
By writing node equation at input port
By writing node equation at output port
From (1) and (2), we have admittance matrix
