Interview Questions- MBA Admissions- Job Interviews
- Electronics and Communication, Applied Electronics
• What is the diffrence between a UPS and an inverter?
"The basic difference in layman's terms is: While both provide backup power during mains outage, with the UPS the switch is instantaneous whereas with the Inverter there is a gap of a second or two. This gap is OK for household gadgets such as lights, fans, fridge, etc. but not OK for computers. In technical terms:UPS: The mains power comes to the UPS. The AC is converted to DC and this DC is constantly charging the battery. The output of the battery is fed to the Sine wave inverter and it converts DC to AC and this feeds the equipment. Since power out is always drawn from the battery, there is no time lag when mains swicthes off; it justs stops the battery from being charged and the UPS continues to supply power till the battery runs out. Inverter: The mains power comes to the Inverter. This is directly sent to the output but the AC is also converted to DC and this DC is constantly charging the battery. A sensor and relay mechanism checks whether the mains is ON or OFF. When the main switches OFF, the relay actuator triggers to switch from mains to inverter. Rest is same like the UPS. Because of this sensor and relay, there is a gap between triggering. UPS involves more costly circuitary and is therefor more expensive to make and sell."
• what is fuzzy Logic?
Fuzzy logic is basically about dealing with not only 0 or 1 but also values in between them i.e.floating values
• How many type of resistances are there in a diode
Two, one when forward biased have zero resistance and the other when reverse biased has infinite resistance
· Why a MOSFET is preferred over a transistor?
A MOSFET is very small in size as compared to a transistor and its biasing is easier as compared to latter.
• Why biasing is required in a transistor?
Biasing is required to get the loadline and the operating point of a transistor.Moreover different regions are achieved through different biasing types.
• How different regions are got and what are those regions?Explain taking a Common Base connection.
Transistor can be biased in 3 different types to get three different regions-Active region,Saturation Region,Cut-off Region
• Explain Active Region- Explain taking a Common Base connection.
Active Region-:Emitter is forward biased and collector is reverse biased
• Cut-off Region- Explain taking a Common Base connection.
Cut-off Region-:Both emitter and collector are reverse biased
• Saturation region:-Explain taking a Common Base connection.
Saturation region:Both emitter and collector are forward biased
• What is a tunnel diode ?
Tunnel diode was invented by Esaki and its different from the normal diode in terms of the doping concentration as in 1part of doping is present in 10^3 atoms whereas in normal diode it is 1 part in 10^8 atoms. It is basically used for very fast switching response.
• Why is a common collector called an emitter follower..?
In this configuration the voltage gain is equal to unity and hence a change in base voltage appeears as an equal change across the load at the emitter.Thus the emitter follows the input signal. The most common use of this circuit is to use as a buffer stage which functions as resistance transformation from high to low resistance.
