Basic Electronics Interview Questions
Electronics Graduates..Are you ready for interview? Here is some useful stuff, where you can brush up the basics in Electronics and Communication Engineering. Q. What is engineering? A. The application of science to the needs of humanity and a profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to use economically the materials and forces of nature for the benefit of mankind. Q. What is the difference between Electronics and Electrical? A. Electronics work on DC and with a voltage range of -48vDC to +48vDC. 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. Examples: Computer, radio, T.V, etc... Electric devices use line voltage (120vAC, 240vAC, etc...). Electric devices can also be designed to operate on DC sources, but will be at DC voltages above 48v. Examples: are incandescent lights, heaters, fridge, stove, etc... Q. What is Electronics? A. The study and use of electrical devices that operate by controlling the flow of electrons or other electrically charged particles. Q. What is Communication? A. Communication means transferring a signal from the transmitter which passes through a medium then the output is obtained at the receiver. (or)communication says as transferring of message from one place to another place called communication. Q. Define the terms. A 1.Resistor: A resistor is an electrical component that limits or regulates the flow of electrical current in an electronic circuit. 2.Capacitor : A capacitor is a passive electronic component that stores energy in the form of an electrostatic field. 3.Diode: A diode is a semiconductor device with two terminals, typically allowing the flow of current in one direction only. 4.Transistor: A transistor is a semiconductor device that regulates current or voltage flow and acts as a switch or gate for electronic signals. Q. What is microprocessor? A. A microprocessor is a program controlled semi conductor device (IC), which fetches, decodes and execute instructions. Q. What is microcontroller? A. A microcontroller is a single chip that contains the processor (the CPU), non-volatile memory for the program (ROM or flash), volatile memory for input and output (RAM), a clock and an I/O control unit. Q. What are the basic units of microprocessor? A. The basic units or blocks of microprocessor are ALU, an array of registers and control unit. Q. What is a bus? A. Bus is a group of conducting lines that carries data, address and control signals. Q. What is a signal? A. a signal is an electric current or electromagnetic field used to convey data from one place to another. Q. What is sampling? A.The process of obtaining a set of samples from a continuous function of time x(t) is referred to as sampling. Q. State sampling theorem. A.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 frequency and the minimum sampling rate is known as the Nyquist rate. Q. What is cut-off frequency? A. The frequency at which the response is -3dB with respect to the maximum response. Q. What is pass band? A. Passband is the range of frequencies or wavelengths that can pass through a filter without being attenuated. Q. What is the principle of microwave? A. Microwave essentially means very short wave. The microwave frequency spectrum is usually taken to extend from 1GHZ to 30GHZ. The main reason why we have to go in for microwave frequency for communication is that lower frequency band are congested and demand for point to point communication continue to increase. The propagation of the microwave takes place in spacewave in view of high gain and directivity in the form of a bean and is similar to that of light. Q. What is latch up? A.Latch-up pertains to a failure mechanism wherein a parasitic thyristor (such as a parasitic silicon controlled rectifier, or SCR) is inadvertently created within a circuit, causing a high amount of current to continuously flow through it once it is accidentally triggered or turned on. Depending on the circuits involved, the amount of current flow produced by this mechanism can be large enough to result in permanent destruction of the device due to electrical overstress (EOS) . Q.Why is NAND gate preferred over NOR gate for fabrication? A.NAND is a better gate for design than NOR because at the transistor level the mobility of electrons is normally three times that of holes compared to NOR and thus the NAND is a faster gate.