What is transformer in electrical engineering? What type of transformer we use at power stations?

transformer

Transformer

Transformer is a device that can increase or decrease the primary voltage, it is one of the most useful device in electrical engineering specially in power transmission, In street usually step down transformers are used because the source voltage that directly come from grid stations is too high to use consume it to our home electrical appliance so transformers are used to decrease the voltage(usually 220v) so that it can be used at homes without damaging any appliance But at power stations we usually use step up transformers to increase the voltage as in power transmittion current and voltage have inverse relationship  so by increasing the voltage the current will decrease that has a a lot of benefits but one of the biggest benefit is by decreasing current there will be less power loss during power transmitting because according to power formula(P=I^2R) current has square time relationship with power so even small increment in current may cause huge loss so this is why we use step up transformers at power stations.

What is Work done and it's derivative.

work done application and formula

Work done

In our daily life work is considered as doing some effort, but in Physics it has entirely different concept, Any body doing work on other body means the first body is applying some to displace other body in other words if one body changes position of other body by applying some force that means the first body is doing some work over other, it can be expressed in mathematical equation as work done is equal to the product of force and displacement(i,e W=f.d) but when we apply the force at some angle we will have to include cosine function in the equation so it will becomeW=fdcos(theta) here theta is angle at which force is being applied to the body if we further rearrange the equation we will find that work is also product of rate of chsngr of momentum and displacement (i.e)

W=f.d we know that f=ma'

so W=ma.d since a=(vf-vi)/t here vf and vi are the final and initial velocities respectivey

=> W={(mvf-mvi)/t}xd

hence this equation is showing that work can also be defined as product of rate of change of momentum and displacement.

Some important MCQ's

MCQs # 1The periodic alternations of sound between maximum and minimum loudness is called ______.

A.Pitch of sound

B.frequency of sound

C.Beats of sound

D.Quality of sound

Answer:C

Explanation: It's definition 

MCQs # 21 torr is equal to to:

A.13.3 N/m^2

B.1.33 N/m^2

C.133.3 N/m^2

D.0.133 N/m^2

Answer: C

MCQs # 3Kilo watt-hour is unit of;

A.Power

B.Work

C.Energy

D.both  B&C

Answer: D

MCQs #4What is average density of earth?

A.5000 kg/m^3

B.5500  kg/m^3

C.4000 kg/m^3

D.4500 kg/m^3

Answer:B

Introduction to physics

                             

Physics

 INTRODUCTION

What is Physics?

Physics is the branch of science that deals with the study of matter and energy,

What is matter and Energy?

In Physics, matter is simply anything that occupy some space and having some weight however energy is

complex thing in physics, something that done scientifically work has some energy so energy can be defined as "Ability to do Work".

What is work?

Physics define work as Any external energy displace a body by applying some external force is called work done.

THIS IS INTRODUCTION KEEP FOLLOWING THIS SITE FOR FURTHER COURSE THANKS.