Wednesday, March 23, 2016

Star-Delta transformation

Find $R_a$?

Solution:
                $R_a=R_1+R_2+\frac{R_1R_2}{R_3}$

  • If $R_1=R_2=R_3=R_Y$ then find $R_{\Delta }$?
      Solution: $R_{\Delta }=3R_Y$

Series and Parallel circuits practice exercise

Problem 1:

Find $R_{ab}$=?
        $R_{cd}$=?
        $R_{ac}$=?

Solution: $R_{ab}=\left(R_1+R_3\right)=R_{ad}$
               $R_{cd}=\left(R_1+R_3\right)=R_{cb}$
               $R_{ac}=\left(R_1+R_2\right)$

Series and Parallel

Problem 1:

Find $R_{ab}$?


Solution: $R_{ab}=R_1+R_2$


Capacitors in Parallel

$C_T=C_1C_2$

Capacitors in Series

Find Equivalent Capacitance between a and b ($C_T$)?  

Solution: $C_T=\frac{C_1C_2}{C_1+C_2}$

Energy stored in Capacitor

$E=\frac{1}{2}Cv^2$

Energy stored in Inductor

$E=\frac{1}{2}Li^2$

Current through Inductor

$i=\frac{1}{L}\int Vdt$

Voltage across Capacitor

$V_c=\frac{1}{C}\int _0^ti\left(t\right)dt$

Tuesday, March 22, 2016

Parallel Circuit

Find $I_1$, $I_2$, $I_3$, $I$?

Solution: $I_1=\frac{V}{R_1}$

$I_2=\frac{V}{R_2}$
$I_3=\frac{V}{R_3}$

$I=I_1+I_2+I_3$

$I=\frac{V}{R_1}+\frac{V}{R2}+\frac{V}{R_3}$

$I=\frac{V}{R_1+R_2+R_3}$

Series Circuit

Find I?


Solution: $I=\frac{V}{R_1+R_2+R_3}$

Basic circuit

Find I?

Solution: $I=\frac{V}{R}$