Infosys Technical Interview Questions for ECE
Infosys Technical Interview Questions for ECE Freshers 2022
For ECE freshers interviewing at Infosys, we have provided Technical Interview Questions that are commonly asked.
Technical Interview for ECE
Apart from Programming and Coding Interview Questions, candidates belonging to ECE branch can expect questions from their core subjects as well. This also includes final year project explanation and important circuital diagrams.
Top 40 Technical Interview Questions for ECE Freshers
Question 1: What is Cut off frequency?
Answer:-
The frequency at which the response is -3dB with respect to the maximum frequency is Cut off frequency.
Question 2: What is Op-amp?
Answer:-
An Operational Amplifier or Op-Amp is a DC- coupled high gain electronica voltage amplifier with differential inputs and usually a single output. Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain by positive feedback, which facilitates regenerative gain and oscillation.
Question 3: What is Transistor?
Answer:-
A transistor is a semiconductor device used to amplify or switch electronic signals. It is the fundamental building block of computers.
Question 4: What is Diode?
Answer:-
A diode is a two-terminal device. It consists of two active electrodes between which the signal of interest flows. They are used for their unidirectional current property.
Question 5: What is a Semiconductor?
Answer:-
A semiconductor is a solid material having electrical conductivity in between that of a conductor and an insulator.
Question 6: What is a conductor?
Answer:-
A conductor is a substance or body which readily conducts heat, electricity, sound, etc. For example, Copper is a good conductor of electricity.
Question 7: What is an inductor?
Answer:-
An inductor is a passive electrical device employed in electrical circuits for its property of inductance.
Question 8: What is a Capacitor?
Answer:-
A capacitor stores energy in the electric field between a pair of conductors. The process of storing energy in the capacitor is known as “charging” and involves electric charges of equal magnitudes. Capacitors are also referred as condensers.
Question 9: What is a Resistor?
Answer:-
A resistor is a two-terminal electronic component that opposes an electric current by producing a voltage drop between its terminal in proportion to the current, which is by Ohm’s law: V = IR.
Question 9: What is a Rectifier?
Answer:-
A rectifier changes alternating current into direct current. They are of three types:-
- half-wave
- full wave
- bridge
Question 10: What is a Half-Wave Rectifier?
Answer:-
Half-Wave Rectifier is the simplest type of rectifier. It can be made with only one diode. When the voltage of the alternating current is positive the diode becomes forward biased and current flows through it. When the voltage is negative, the diode is reverse biased and the current stops.
Question 11: What is a Full-Wave Rectifier?1
Answer:-
Full-Wave Rectifier is two halfwave rectifiers. It is made with two diodes and an earthed center tap on the transformer. The positive voltage half of the cycle flows through one diode and the negative half flows through the other. The center tap allows the circuit to be completed because current cannot flow through the other diode. The result is a pulsating direct current with just over half the input peak voltage and double the frequency.
Question 12: What is an Integrated Circuit?
Answer:-
An Integrated Circuit or IC, is a microchip. It is an electronic circuit that is etched onto a silicon chip. Their main advantage is low cost, power, high performance and compact size.
Question 13: What is a Transducer?
Answer:-
The transducer is a device that converts one type of energy to another for various purposes including measurement or information transfer.
Question 14: What is a Transponder?
Answer:-
Transponder transmits a predetermined message in response to a predetermined received signal. It generates a reply signal on proper electronic interrogation.
Question 15: What is a Transponder?
Answer:-
Transponder transmits a predetermined message in response to a predetermined received signal. It generates a reply signal on proper electronic interrogation.
Question 16: What is Crosstalk?
Answer:-
Crosstalk is a form of interface caused by signals in nearby conductors. It occurs in radios, televisions, telephones, etc.
Question 17: What is an Oscillator?
Answer:-
Oscillator produces a waveform output with a DC input. They are of two types, harmonic and relaxation.
Question 18: Give an example for positive feedback.
Answer:-
An example of positive feedback is oscillators.
Question 19: Give an example for negative feedback.
Answer:-
An example of negative feedback is amplifiers.
Question 20: What is feedback?
Answer:-
Feedback is a process where some portion of the output signal is passed to the input signal. It is used to control the behavior of the system.
Question 21: What are the types of feedback?
Answer:-
There are two types of Feedback:-
- negative feedback
- positive feedback
Question 22: What is the advantage of negative feedback over positive feedback?
Answer:-
Negative feedback processes leads a system towards equilibrium. While the positive feedback tends to lead the system away from equilibrium, causing disruptions.
Question 23: What is Full Duplex?
Answer:-
Full Duplex is the simultaneous transmission of data in two directions. For example a mobile is a full duplex device, where both parties can talk at once.
Question 24: What are Barkhausen criteria?
Answer:-
“Oscillations will not be sustained if, at the oscillator frequency, the magnitude of the product of the transfer gain of the amplifier and the magnitude of the feedback factor of the feedback network ( the magnitude of the loop gain ) are less than unity”.
The condition of unity loop gain Aβ = 1 is called the Barkhausencriterion. This condition implies that | Aβ|= 1and that the phase of – Aβ is zero.
Question 25: What is an amplifier?
Answer:-
An amplifier is an electronic device used to boost the power, voltage or current of an applied signal.
Question 26: What is GSM?
Answer:-
GSM or Global System for Mobile Communications uses narrowband TDMA. It allows eight simultaneous calls on the same radio frequency. TDMA divides radio frequency into time slots and then allocates these slots to multiple calls. This leads to a single frequency can support multiple, simultaneous data channels.
Question 27: What is CDMA?
Answer:-
CDMA or Code Division Multiple Access is a channel access method, utilized by various communication technologies. It employs a spread spectrum technology and a special coding scheme (where each transmitter is assigned a code) to allow multiple users to multiplexed over the same physical channel.
Question 28: What do TDMA and FDMA stand for?
Answer:-
TDMA:- Time Division Multiple Access
FDMA:- Frequency Division Multiple Access
Question 29: What is Multiplexing?
Answer:-
Multiplexing combines multiple analog message signals or digital data streams into one signal over a shared medium.
Question 30: What is Attenuation?
Answer:-
Attenuation is the reduction in amplitude and intensity of the signal. It is an important property in telecommunications and ultrasound applications because of its importance in determining signal strength as a function of distance.
Question 31: What is a Repeater?
Answer:-
A repeater is an electronic device that retransmits signals at a higher level onto the other side of an obstruction, so that the signal can cover long distance without degradation.
Question 32: How many satellites are required to cover the earth?
Answer:-
Three satellites are required to cover the entire earth. They need to be placed at 120 degrees from each other.
Question 33: What is a Base Station?
Answer:-
Base Station serves as the hub of local wireless network. It acts as a gateway between wired and wireless network.
Question 34: What do you mean by AM and FM?
Answer:-
AM:- Amplitude Modulation is a type of modulation where the amplitude of the carrier signal is varied in accordance with the information bearing signal.
FM:- Frequency Modulation is a type of modulation where the frequency of the carrier signal is varied in accordance with the information bearing signal.
Question 35: Where do we use AM and FM?
Answer:-
AM is used for video signals. For example: TV Ranges from 535 to 1705 kHz.
FM is used for audio signals. For example: Radio ranges from 88 to 108 MHz.
Question 36: Name the modulation techniques.
Answer:-
For Analog Modulation- AM, SSB, FM, PM and SM.
For Digital Modulation- OOK, FSK, ASK, PSK, QAM, MSK,CPM, PPM, TCM, OFDM.
Question 37: What is Demodulation?
Answer:-
Demodulation is the act of removing the modulation from an analog signal to get the original baseband signal back. Demodulating is necessary because the receiver system receives a modulated signal with specific characteristics and it needs to turn it to baseband.
Question 38: What is Modulation? And where is it utilized?
Answer:-
Modulation is the process of varying some characteristic of a periodic wave with an external signal. Radio communication super imposes this information bearing signal onto a carrier signal. These high frequency carrier signals can be transmitted over the air easily and are capable of travelling long distances.
Question 39: Explain RF.
Answer:-
RF or radiofrequency is the rate of oscillation within the range of about 3Hz to 300 GHz. This range corresponds to the frequency of alternating current electrical signals used to produce and detect radio waves. Since most of this range is beyond the vibration rate the most mechanical system can respond to RF usually refers to oscillations in electrical circuits or electromagnetic radiation.
Question 40: What is a Stop Band?
Answer:-
Stop Band is a band of frequencies between specified limits, in which a circuit does not let a signal through or the attenuation is above the required stopband attenuation level.
Question 41: What is Sampling Theorem?
Answer:-
Sample Theorem states that while taking the samples of a continuous signal, it has to be taken care that the sampling rate is equal or greater than twice the cut off frequency and the minimum sampling rate is known as Nyquist rate.
Question 42: What is a Pass Band?
Answer:-
Pass Band is the range of frequencies or wavelengths that can pass through a filter without being attenuated.
Question 43: What is Sampling?
Answer:-
The process of obtaining a set of samples from a continuous function of time x(t) is referred to as sampling.
Question 44: What do you mean by an Electronics device?
Answer:-
Electronics work on DC and with a voltage range of 48V DC to +48V DC. If the electronic device is plugged into a standard wall outlet, there will be a transformer inside which will convert the AC voltage you are supplying to the required DC voltage needed by the device.
For Example, Computers, Radio, TV
Question 45: What do you mean by an Electrical device?
Answer:-
Electric devices use line voltage. They can also be designed to operate on DC sources, but will be at DC voltage above 48V.
For example, incandescent lights, heaters, fridge.
