• Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

suddenly the minus pops up formula

Status
Not open for further replies.
i know the formula for flux and inductance
[latex]\phi=LI[/latex]

BUT
[latex]\epsilon=-\dot{\phi}=-L\dot{I}[/latex]
but when i learned circuit theory
i always had these formulas
for inductor
[latex]\epsilon=L\dot{I}[/latex]
and for capacitor
for inductor
[latex]I=C\dot{V}[/latex]

there where no minus in the inductance formula

why in physics they add minus
??
 

skyhawk

New Member
Because it was connected with a certain convention for tracing around a loop. As you go around a loop you have rules for calculating the voltage across an element based on the direction you pass through relative to the assumed current flow. There can be various conventions for doing this. You must use a consistent set of rules.
 
Status
Not open for further replies.

EE World Online Articles

Loading
Top