Resistance property

Electrical resistance is also outlined because the basic property of any substance owing to that it resist the flow of current through it. Laws of Resistance :- Ohm's Law :- Ohm's law states that the present through a conductor between 2 points is directly proportional to the potential across the 2 points. Introducing the constant of proportion, the resistance, one arrives at the same old mathematical equation that describes this relationship. I = \frac,

The current through any conductor depends upon variety of electrons passes through a cross-sectional per unit time. therefore if cross section of any conductor is giant then a lot of electrons will cross it meaning a lot of current will flow through the conductor. For mounted voltage, a lot of current means that less ohmic resistance. therefore it may be all over like that resistance of any conductor is reciprocally proportional to its cross-sectional space. If the length of the conductor is inflated, the trail traveled by the electrons is additionally increased . If electrons travel long, they collide a lot of and consequently the amount of electron passing through the conductor becomes less; thence current through the conductor is reduced. In alternative word, resistance of the conductor will increase with impedance.

The resistance law state that,Electrical resistance R of a conductor or wire is directly proportional to its length, l i.e. R ∝ l,inversely proportional to its space of cross-sectional, a i.e.Combining these 2 laws we have a tendency to get,

Where ρ (rho) is that the proportion constant and referred to as impedance or specific resistance of the fabric of the conductor or wire. currently if we have a tendency to place, l = one and a = one within the equation, We get, R = ρ. meaning resistance of a cloth of unit length having unit cross - sectional space is adequate its impedance or specific resistance. impedance of a cloth may be alliteratively outlined because the ohmic resistance between opposite faces of a unit cube of that material. thence we've seen that laws of resistance ar terribly straightforward. Unit of impedance :- The unit of impedance may be simply determined kind its equation The unit of impedance is Ω-m in MKS system and Ω-cm in cgs and one Ω-m = one hundred Ω-cm.

Create password protected folder programming

cls
@ECHO OFF
title Folder Locker
if EXIST "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}" goto UNLOCK
if NOT EXIST Locker goto MDLOCKER
:CONFIRM
echo Are you sure u want to Lock the folder(Y/N)
set/p "cho=>"
if %cho%==Y goto LOCK
if %cho%==y goto LOCK
if %cho%==n goto END
if %cho%==N goto END
echo Invalid choice.
goto CONFIRM
:LOCK
ren Locker "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
attrib +h +s "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
echo Folder locked
goto End
:UNLOCK
echo Enter password to Unlock folder
set/p "pass=>"
if NOT %pass%==type your password here goto FAIL
attrib -h -s "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}"
ren "Control Panel.{21EC2020-3AEA-1069-A2DD-08002B30309D}" Locker
echo Folder Unlocked successfully
goto End
:FAIL
echo Invalid password
goto end
:MDLOCKER
md Locker
echo Locker created successfully
goto End
:End

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Hi this isTapas Kumar (Post Diploma inThermal Power,New Delhi ,India). Here u can learn about whole electrical engineering by simply clicks.And you can learn more about more with me.

Faraday's Law's of Electromagnetic Induction

In the whole electrical machines works on those principle

First Law :- If there is a relative motion between conductor(coil) and magnetic field then emf                                   (voltage) will be induced in that coil or conductor.

                                            The induced emf are of two type........

                                                        i. Dynamic induced emf ( conductor is moving)

                                                        ii. Static induced emf ( conductor or coil will fixed)

Second Law :-  Magnitude of the induced emf is Directly proportional to the rate of change of flux.

                              

                             i) According to faraday's of electromagnetic induction the induced voltage 

    

                           E=N dΦ/dt