The next stop in our journey of Interview Question Banks is that of Micromax Informatics Limited. It is an Indian consumer electronics & telecommunication firm which was established as IT software company operating in embedded services domain and later entered into mobile handset business. Let’s now look at some of the questions asked in its interviews in recent times…
Q : Why do we gradually increase the size of inverters in buffer design & not give the output of a circuit to one large inverter?
A : We gradually increase the size to get an optimized performance as it cannot drive the output load straight away.
Q : How will you generate a rectangular wave?
A : There are two ways for generating a rectangular wave – using Schmitt trigger circuit, and using a DAC (Digital to Analog Converter) along with a microprocessor having software delays of appropriate time period.
Q : What is Body Effect?
A : Generally, multiple MOS devices are made on a common substrate. Thus, the substrate voltage of all devices is normally equal. However, while connecting the devices serially, this may result in an increase in source-to-substrate voltage as we proceed vertically along the series chain (Vsb1=0, Vsb2=0) .This results in Vth2>Vth1.
Q : Why is the substrate in NMOS connected to Ground and to VDD in PMOS?
A : We have to try to maintain the drain-source junctions reverse biased with respect to the substrate so that current does not enter into the substrate.
Q : How do you define selectivity in a radio receiver?
A : Selectivity is defined as the ability to select the required band of frequencies and reject the unwanted ones.
Q : What is the fundamental difference between a MOSFET and BJT ?
A : Firstly, BJT is a current controlled device and MOSFET is a voltage controlled device. Secondly, current flow in BJT is due to both electrons and holes but in MOSFET, the current flow is due to either of them only (holes in PMOS & electrons in NMOS).
Q : What is difference between latch and flip-flop?
A : Please follow the link to read about the differences between latch and flip-flop.
Q : What is the purpose of using a tuned circuit between stages in the radio receiver?
A : The main purpose is to increase the sensitivity and selectivity of the radio receiver.
(Continued to Part 2…)
Gautam Vashisht