# Electronics Engineering - Online Test

Q1. A plane wave of wavelength λ is traveling in a direction making an angle 300 with positive x − axis and 900 with positive y − axis. The  field of the plane wave can be represented as (E is constant)
Explaination / Solution:

Q2. A p n junction has a built-in potential of 0.8 V. The depletion layer width a reverse bias of 1.2 V is 2 μm. For a reverse bias of 7.2 V, the depletion layer width will be
Explaination / Solution:

Q3.
An open loop system represented by the transfer function  is
Explaination / Solution:

Open loop system stability is depends only on pole locations ⇒ system is stable There is one zero on right half of s-plane so system is non – minimum phase

Q4. The fourier series expansion  of the periodic signal shown below will contain the following nonzero terms

Explaination / Solution:

⇒ it satisfies the half wave symmetry, so that it contains only odd harmonics.
⇒ It satisfies the even symmetry. So bn = 0

Q5. Consider the following statement (i) The compensating coil of a low power factor wattmeter compensates the effect of the impedance of the current coil. (ii) The compensating coil of a low power factor wattmeter compensates the effect 0of the impedance of the voltage coil circuit.
Explaination / Solution:
No Explaination.

Q6. A low – pass filter with a cut-off frequency of 30Hz is cascaded with a high-pass filter with a cut-off frequency of 20Hz. The resultant system of filters will function as
Explaination / Solution:

Q7. A three-phase current source inverter used for the speed control of an induction motor is to be realized using MOSFET switches as shown below. Switches S1 to S6 are identical switches.
The proper configuration for realizing switches S1 to S6 is
Explaination / Solution:
No Explaination.

Q8. The voltage applied to a circuit is  volts and the circuit draws a current of  amperes. Taking the voltage as the reference phasor, the phasor representation of the current in amperes is
Explaination / Solution:

Q9. The minterm expansion of f
Explaination / Solution:
No Explaination.

Q10. The circuit shown is a

Explaination / Solution: