Engineering Viva Questions

 Viva Questions on  Transistor as an Amplifier Short Viva Questions with Answers o n  Transistor as an Amplifier Q.1. What are the Hybrid Parameters (h-parameters)? Explain. Ans. Hybrid parameters are also called as h-parameters. Characteristics of amplifier can be specified easily in terms of h-parameters. The hybrid or h-parameters are very popular and widely used because them give accurate result and can be measured very easily. We know that a transistor is a three terminals device. If one terminal is made common to the Input and output, then the transistor can be represented as a two-port network. Q.2. What do you mean by cascade amplifier? Ans. Cascade amplifier is a composite amplifier pair with a large bandwidth used for RF applications and as a video amplifier. It consists of a CE stage followed by a CB stage directly to each   other and combines some of the features of both the amplifiers. For high frequency applications, CB configuration h...

Viva Questions With Answers Q.1. What is feedback? Ans. The feedback may be defined as a process of injecting some energy from the output and then return it back to the input. In other words, when a part or fraction of output is combined with the input, feedback is said to exist. Q.2. What are the types of feedback? Ans. Depending upon whether the feedback signal increases or decreases the input signal, there are two basic types of feedback in amplifiers. (i)                  Positive Feedback (ii)                Negative Feedback Q.3. Write the expressions for voltage gain with negative & positive feedback. Ans. The voltage gain with negative feedback will be Similarly, we can compute the voltage gain with positive feedback i.e., Q.4. List the merits of negative feedback. Ans. (i)    ...

  Semiconductor Devices Viva Questions Q.1. What is doping? Ans. The process of adding impurity to a pure semiconductor is called doping. Doping is done at a rate such that only one atom of impurity is added per 10 6 to 10 10 semiconductor atoms. Q.2. What are the types of extrinsic semiconductor? Ans. Depending upon the types of impurity added, there are two types of extrinsic semiconductors: (a) N-type semiconductor (b) P-type semiconductor Q.3. What is the energy gap? Ans. The energy gap between the valence band and conduction band is known as the forbidden energy gap. A forbidden energy gap is a region in which no electron can stay as there is no allowed energy state. The greater the forbidden energy gap more tightly the valence electrons are bound to the nucleus. Q.4. Define diode resistance. Ans. An ideal diode offers zero resistance when forward bias and infinite resistance when it is reverse biased. But practical or real diode does not beha...