A 560 , a 380 , and a 325 resistor are connected in parallel across a 120V battery. What is the total resistance of the circuit? What is the circuit current? What is the current through each resistor? What is the power dissipated?

Respuesta :

Answer:

(a). Total resistance of the circuit R = 133.43 ohm

(b).  Current I = 0.9 A

(c). Current in each resistor [tex]I_1[/tex] = 0.214 A ,  [tex]I_2[/tex] = 0.315 A & [tex]I_3[/tex] = 0.369 A

(d). Power dissipated through the circuit is  P = 108 W

Explanation:

Given data

[tex]R_{1}[/tex] = 560 ohm

[tex]R_2[/tex] = 380 ohm

[tex]R_3[/tex] = 325 ohm

Voltage V = 120 V

(a).Total resistance of the circuit in case of parallel circuit is given by

[tex]\frac{1} {R} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3}[/tex]

[tex]\frac{1}{R} = \frac{1}{560} + \frac{1}{380} + \frac{1}{325}[/tex]

R = 133.43 ohm

(b).  We know that from ohm's law

Voltage V = I R

120 = I × 133.43

I = 0.9 A

This is the value of current in the circuit.

(c). Current in resistor one

[tex]I_1 = \frac{V}{R_1}[/tex]

[tex]I_1 = \frac{120}{560}[/tex]

[tex]I_1[/tex] = 0.214 A

Current in  second resistor

[tex]I_2 = \frac{V}{R_2}[/tex]

[tex]I_2 = \frac{120}{380}[/tex]

[tex]I_2[/tex] = 0.315 A

Current in third resistor

[tex]I_3 = \frac{V}{R_3}[/tex]

[tex]I_3 = \frac{120}{325}[/tex]

[tex]I_3[/tex] = 0.369 A

(d). Power dissipated through the circuit is given by

P = V I

P = 120 × 0.9

P = 108 W