Top Interview Questions in Electronics

QàIn a power grid why are the high tension lines are proubs of three line and not four?

Aà Because the lines are connected between two Δ transformers.

Qà What are the factors to be considered for selecting the operating point?

Aà While selecting the operating point the following factors are to be considered
DC and AC loads at the output of the stages
The maximum transistor rating.
The available power supply.
The peak signal execution to be handled by the amplifier.
The tolerance distortion.

Qà What is the differences between the microcontroller and microprocessor?

Aà The microprocessor is the integration of a number of useful functions into a single IC package. These functions are:
The ability to execute a stored set of instructions to carry out user defined tasks.
The ability to be able to access external memory chips to both read and write data from and to the memory.
On the otherhand, a microcontroller is a device which integrates a number of the components of a microprocessor system onto a single microchip.
So a microcontroller combines onto the same microchip :
The CPU core
Memory (both ROM and RAM)
Some parallel digital I/O
Most microcontrollers will also combine other devices such as:
A Timer module to allow the microcontroller to perform tasks for certain time periods.
A serial I/O port to allow data to flow between the microcontroller and other devices such as a PC or another microcontroller.
An ADC to allow the microcontroller to accept analogue input data for processing.

QàDifference between sdram and ddram?

Aà SD Ram is actually SDR SDRAM, and DD Ram is actually DDR SDRAM, though the former does not usually have the SDR in front of it. The letters SDR and DDR stand for Single Data Rate and Double Data Rate, and the letters SDRAM stand for Synchronous Dynamic Random Access Memory. The main difference between SDR and DDR memory is speed. There are a lot of little differences, but the main one (IMHO) that affects the user is speed: DDR can transfer data at roughly twice the speed of SDR. More speedy data rates = better performance. Just remember, the motherboard you are using must include the appropriate chipset to support the different RAM types. They are not interchangeable. SDR SDRAM comes in three main flavors: PC66, PC100 and PC133. Each successive number refers to the bus speed of the RAM in MHz, thus PC66 runs at 66 MHz, PC100 runs at 100 MHz, etc. SDR SDRAM has 168 pins at the connector. DDR SDRAM has 184 pins at the connector, which is one reason you can't just use DDR instead of SDR, and comes in many different flavors; PC2100 which runs at 266 MHz, PC2700 which runs at 333 MHz, PC3200 which runs at 400 MHz, etc. In order to know which type of RAM you need, you must know what your motherboard supports.

Qà Difference between data processors and dsp?

Aà In data processing or information processing, a Data Processor or Data Processing Unit or Data Processing System is a system which processes data which has been captured and encoded in a format recognizable by the data processing system or has been created and stored by another unit of an information processing system.

On the other hand DSP is a specialized digital microprocessor used to efficiently and rapidly perform calculations on digitized signals that were originally analog in form (eg voice). The big advantage of DSP lies in the programmability of the processor, allowing parameters to be easily changed.

Qà Tell about harvard architecture?

Aà The term Harvard architecture originally referred to computer architectures that used physically separate storage and signal pathways for their instructions and data (in contrast to the von Neumann architecture). The term originated from the Harvard Mark I relay-based computer, which stored instructions on punched tape (24-bits wide) and data in relay latches (23-digits wide). These early machines had very limited data storage, entirely contained within the data processing unit, and provided no access to the instruction storage as data (making loading, modifying, etc. of programs entirely an offline process).

QàDo you smoke ?

AàOnly when i have burned a bit and been blown out !

Qà What is a transformer ?

AàA transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field through the secondary winding. This varying magnetic field induces a varying electromotive force (EMF), or "voltage", in the secondary winding. This effect is called inductive coupling.

If a load is connected to the secondary, current will flow in the secondary winding, and electrical energy will be transferred from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (V_s) is in proportion to the primary voltage (V_p) and is given by the ratio of the number of turns in the secondary (N_s) to the number of turns in the primary (N_p) as follows:

By appropriate selection of the ratio of turns, a transformer thus enables an alternating current (AC) voltage to be "stepped up" by making N_s greater than N_p, or "stepped down" by making N_s less than N_p.

In the vast majority of transformers, the windings are coils wound around a ferromagnetic core, air-core transformers being a notable exception.