Larsen & Toubro (L&T) Infotech, a Larsen & Toubro Ltd’s subsidy, is a global IT services and solutions company headquartered in Mumbai. L&T Infotech is ranked #6 in IT companies in India. There are 39 registered offices of the company in 27 countries. The company employs standards of Capability Maturity Model Integration (CMMI) from Software Engineering Institute (SEI) and is assured of Maturity Level 5. The new CEO and MD of L&T Infotech is Mr. Sanjay Jalona.
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L&T Interview Questions and Answers for Electronics
L&T Infotech conducts interview process for electronics & communications. Listed here are the top interview questions during the process
What is Electronics?
Electronics is the use of electrical equipment and their study to operate by controlling the electrons’ flow or particles that are electrically charged.
What is Communication?
Communication refers to transmitting the signal from transmitter passing with a medium and output is then received. Simply speaking, it is transferring signal from one place to another.
Explain the Types of Communications
There are two types of communications – Analog and Digital. Analog takes video and audio signal and translates into electrical pulses. On the other hand, digital signal breaks into binary format where video or audio data is determined with “1” and “0”. Digital signals vary from quality of transmission, noise, and reception is sound and components uses can be generated with great precision and consumption of power is less than analog signals.
What is Cut-Off Frequency?
It is the frequency with -3dB of maximum response rate.
What is Pass Band?
It is the range of wavelengths or frequencies passing through the filter.
What is Sampling?
It is the process of collecting the samples from the consistent function of x(t) time.
What is State Sampling Theorem?
When gathering samples of the consistent signal, make sure that sampling rate is higher than double or similar to the cut-off frequency and least sampling rate or Nyquist rate.
What is Stopband?
It is a band of frequencies in which telephone or filter circuit, between specific limits, doesn’t allow signals or when attenuation is above the needed stop band level.
What is Radio Frequency (RF)?
It is a rate of oscillation or frequency in the specified range of 3Hz to 300GHz. It meets the frequency of alternate current signals that are used to detect radioactive waves. Most of this range is above the vibration rate in mechanical systems.
What is Modulation? Where is it used?
It is the process of differentiating the features of the periodic wave with exterior signals. This information is superimposed with radio communication on the carrier signal. These high-frequency signals can be transferred over the air and can travel long distances. The frequency, amplitude, and phase are the characteristics of the carrier signal that are varied according to the details having the signal. Modulation is used to send details having signals to further distances.
Explain Demodulation
It is the process of removing modulation from the analog signal and gets the original signal again. Demodulation is required as the receiver gets the signal with unique characteristics.
What are the Modulation Techniques?
Digital Modulation – FSK, OOK, ASK, QAM, PSK, MSK, PPM, CPM, OFDM, TCM
Analog Modulation – FM, AM, SSB, PM, SM
What are AM and FM?
Amplitude modulation (AM) is a kind of modulation where the amplitude of the signal is varied according to the information signals.
Frequency modulation (FM) is a kind of modulation where carrier signal’s frequency is varied as per the signal.
Where are AM and FM used?
AM is used for video signals ranging from 535 to 1705 kHz, for ex. TV
FM is used on audio signals ranging from 88 to 108 MHz, for ex. Radio.
How many satellites needed to cover our planet?
To cover the whole earth, three satellites are required placed at 120 degrees to one another. The life span of the satellite should be around 15 years.
What is Repeater?
It is an electronic device used to receive signal and transmits the same at higher power or higher level or on another part of obstruction so the longer distances can be covered without any degradation.
What is Base Station?
It is a radio transmitter/receiver serves as a hub of the wireless network and a gateway between wireless and wired network.
What is Amplifier?
It is an electrical circuit or electronic device to amplify or boost the voltage, power or current of the signal.
What are the examples for positive and negative feedback?
Negative Feedback – Amplifiers
Positive Feedback – Oscillators
What is Integrated Circuit?
Also known as the microchip, an IC or Integrated Circuit is a circuit over a silicon chip. The best thing about IC is low power, low-cost, small size, and high performance.
What is Oscillator?
The oscillator is actually a circuit which makes a waveform output from the actual current input. Relaxation and harmonic are the two types of oscillators. Harmonic oscillators come with curved yet smooth waveforms and relaxation oscillators have sharp changes in waveforms.
I hope these L&T Interview questions and answers for electronics helped you! Prepare well for the interview! All the Best
