Q1. What is Electronics?

Ans: The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles.

 

Q2. What is meant by D-FF?

Ans: D-flip flop stands for Delay flip-flop, it delays input by one clock pulse.

 

Q3. What are the functions of Base Station System (BSS)?

Ans: Functions of BSS are as follows:

• Radio path control.
• BTS and TC control.
• Connection establishment with MS-NSS.
• Mobility management, speech transcending.
• Connection of statistical data.

 

Q4. Define the terms.

Ans:

• Resistor: A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit.
• Capacitor : A capacitor is a passive electronic component that stores energy in the form of an electrostatic field.
• Diode: A diode is a semiconductor device with two terminals, typically allowing the flow of current in one direction only.
• Transistor: A transistor is a semiconductor device that regulates current or voltage flow and acts as a switch or gate for electronic signals.
  
  

Q5. What is the basic difference between Latches and Flip flops?

Ans: Latches are monostable and flip-flops are bistable

 

Q6. What is wireless communication concept ?

Ans:Wireless communication is the transfer of information between two or more points that are not connected by any physical medium.Wireless communications can be via:

• Radio communication.
• Microwave communication.
• Light, Visible and Infrared communication.

 

Q7. What are the parts of Network Management System (NMS)?

Ans: Following are the parts of network management system:

• OMC: Operation and maintenance center – Computerized monitoring center.
• NMC: Network Management Center – Centralized control of a network is done here.
• OSS: Operation and support system – Used for supporting activities performed in an OMC and/or NMC.

Q8. What is a signal?

Ans: A signal is an electric current or electromagnetic field used to convey data from one place to another.

 

Q9. What is a multiplexer?

Ans: It is used to multiplex data from different sources normally used in TDM.

 

Q10. What do you mean by frequency reuse ?

Ans: Each cellular Base Station is allocated a group of radio channels to be used. These radio channels can be used by another base station which is at a suitable distance away from it.

 

Q11. What is sampling?

Ans: The process of obtaining a set of samples from a continuous function of time x(t) is referred to as sampling.

 

Q12. What is Race-around problem? How can you rectify it?

Ans: Race around condition occurs in a JK flip-flop when both the inputs are set to '1', it can be rectified using edge-triggered flip-flop or using master-slave flip-flops.

 

Q13. What do you mean by Handoff ?

Ans: When a mobile moves into a different cell while a conversation is in progress, the Mobile Switching Center automatically transfers the call to a new channel belonging to the new Base Station.
Types of handoff:-
Hard Handoff
Soft Handoff.

 

Q14. State sampling theorem.

Ans: It states that, while taking the samples of a continuous signal, it has to be taken care that the sampling rate is equal to or greater than twice the cut off frequencyand the minimum sampling rate is known as the Nyquist rate.

 

Q15. How can you convert an JK Flip-flop to a D Flip-flop?

Ans: Connect J to D and K to not(D)

 

Q16. What is cut-off frequency?

Ans: The frequency at which the response is -3dB with respect to the maximum response.

Q17. What do you mean by zener breakdown and avalanche breakdown?

Ans: zener breakdown takes place when very high voltage is applied to the diode this results in very high reverse current, as voltage is further increased minority carriers gain further momentum and strike atoms releases more carriers, which results in further increase in temp. It becomes vicious cycle and leads to avalanche breakdown or on other words "thermal runaway".

 

Q18. What are the different types of transmission impairment ?

Ans: When the received signal is not as same as the transmitted signal then it is known as Transmission impairment. Three different types of transmission impairment are:-

• Attenuation.
• Noise.
• Delay Distortion.

 

Q19. What is pass band?

Ans: Passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated.

 

Q20. Explain the steps involved in demodulating a signal.

Ans: Once the signal is coded, modulated and then sent, the receiver must demodulate the signal. This is usually done in two steps: Spectrum spreading (e.g., direct sequence or frequency hopping) modulation is removed.The remaining information bearing signal is demodulated by multiplying with a local reference identical in structure and synchronized with received signal.

 

Q21. What is impulse response?

Ans: Response given by a digital system when impulse signal is applied to it. Used to find out stability of system.

 

Q22. What do you mean by half-duplex and full-duplex communication?

Ans: Half-duplex: either sender or receiver can use the channel at one time eg walky-talky and 

Full-duplex: sender or receiver or both can use the channel at one time eg telephone).

 

Q23. What is Diode?

Ans: Diode is a two terminal electronic component which allows current to flow in one direction.

It acts as a one way switch.

Types of Diode:

Laser Diode

Gunn Diode

Light Emitting Diode

 

Q24. What is Transistor?

Ans: A transistor is an semiconductor device used to amplify or switch electronic signals.

Types:

·        Bi-polar Junction Transistor(BJT)

·        Field Effect Transistor(FET)

·        Insulated-gate bipolar transistor(IGBT)

Q25. What is Oscillator?

Ans: An Oscillator is a circuit which produces AC waveform as output without any input.