During the placement season, we all start to find all the relevant, important and frequently asked interview questions on various websites but cannot find all of them at one place. So, to help you in your campus placement drives, I have prepared a Question Bank of all the questions that were asked to me and my friends in the technical interviews of Aricent Technologies (ECE core company) at the time of our campus placement. I hope this would be beneficial for you to prepare for Aricent and other ECE core companies as well. The answers are prepared in a way that is easily understood and looks a bit technical as well (to make an impression!).
Let’s start with the core ECE technical questions first…
Q-1. What is an oscillator? Give an application of it.
A : Oscillator is a circuit that generates a waveform output for a direct current input. There are mainly two types of oscillators – harmonic (which have smooth curved waveforms) and relaxation (which have waveforms with sharp edges). Example – speakers etc.
Q-2. What is AM? Give a brief description of its working.
A : AM stands for Amplitude Modulation which is an analog modulation technique where amplitude of carrier (high frequency) signal is varied in accordance with the message (low frequency) signal. It is used for video signals for example TV etc. which operate in the frequency range of 535-1705 KHz.
Q-3. What is FM? How does it work? Explain the difference between AM and FM.
A : FM stands for Frequency Modulation which is an analog modulation scheme where frequency of the carrier signal is varied according to the message signal unlike amplitude in AM. For a binary signal which has only two possibilities – 0 and 1, two carriers (with different frequencies) are used for denoting 0 and 1. It is used for audio signals for example Radio etc. which operate in the frequency range of 88-108 MHz.
Q-4. What is modulation and why is it necessary?
A : Modulation is the process of varying the characteristics of a high frequency carrier signal (i.e. amplitude, frequency or phase) in accordance with the low frequency message signal. When a signal is transmitted, noise gets added through the environment, channel/medium of communication, transmitter/receiver incapability etc. which sometimes adversely affects the low frequency signal transmitted (without modulation) resulting in decaying of information to be sent. Thus, the low frequency baseband signal is modulated over a high frequency carrier signal to minimize the effect of noise for effective transmission of information even over long distances.
Q-5. What is demodulation and why is it necessary?
A : Demodulation is the process of removing the modulation from the received analog signal to obtain the original message signal sent by the transmitter in order to interpret the information to be communicated.
Gautam Vashisht, JIIT Noida
Continued in Part 2