(Parallel Circuits) Find: It and Vt?

Question

Find: It, Vt, V1, V2, V3, R1, and R2

 

I1 = 2A  

I2 = 4A

I3 = 6A

 

R1 = ?

R2 = ?

R3 = 8 ohms

 

 

Answer 1

PROBLEM

 

(Parallel Circuits) Find: It and Vt?
Find: It, Vt, V1, V2, V3, R1, and R2

I1 = 2A
I2 = 4A
I3 = 6A

R1 = ?
R2 = ?
R3 = 8 ohms

 

SOLUTION

 

Draw a diagram of the parallel circuit...

 

 -----It-----I4-------

 |          |       |      |

 |          I1     I2    I3

 |          |       |      |

 Vt        R1    R2    R3

 |          |       |      |

 |          |       |      |

 |          |       |      |

 ---------------------

 

We know V = I*R and current entering a node equals current leaving a node, therefore if:

 

I1 = 2A
I2 = 4A
I3 = 6A

R1 = ?
R2 = ?
R3 = 8 ohms

 

Then V3 = I3*R3 = 6*8 = 48 V

 

Because the resistors are in parallel, then V3 = V2 = V1 = Vt = 48 V

 

Since V2 = 48 V and I2 = 4 A, then R2 = V2/I2 = 48/4 = 12 ohms

 

 

Since V1 = 48 V and I1 = 2 A, then R1 = V1/I1 = 48/2 = 24 ohms

 

It = I1 + I2 + I3 = 2 + 4 + 6 = 12 A