Question

Please solve the question guys


Find the total resistance of the circuit
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Answer 1

• Total potential difference, V = 60 volt.

• Current through A is 3 A

• Current through B is 4 A

• Current through C is 5 A

• Current through D is 3 A

The net current flowing across the circuit will be equal to the sum of the current flowing through A , B ,C and D

Net current, I = 3 + 4 + 5 + 3

I = 15 A

Net current across the circuit is 15 ampere.

According to ohms law,

V = IR

Where R is the net resistance

$60 = 15 \times R \\ R = \frac{60}{15} \\ \\ R = \frac{12}{3} \\ \\ R = 4 \: ohm$

The total resistance of the circuit is 4 ohm

ALTERNATIVE METHOD

The net resistance can also be found by finding the individual resistance.

Potential difference is same in parallel connection of circuit.

So potential difference across A , B , C and D are same 60 volt.

RESISTANCE OF A

V = IR

60 = 3 × R

R = 60/3

R = 20 ohm

RESISTANCE OF B

V = IR

60 = 4 × R

R = 60/4 = 30/2

R = 15 ohm

RESISTANCE OF C

V = IR

60 = 5 × R

R = 60/5

R = 12 ohm

RESISTANCE OF D

V = IR

60 = 3 × R

R = 60/3

R = 20 ohm

The net resistance in parallel circuit will be,

1/R = 1/20 + 1/15 + 1/12 + 1/20

1/R = 2/20 + 1/15 + 1/12

1/R = 1/10 + 1/15 + 1/12

1/R = (18 + 12 + 15) /180

1/R = 45/180

R = 180/45

R = 4 ohm