Question

The current in a circuit is tripled by connecting a 580 resistor in parallel with the resistance of the circuit. Determine the resistance of the circuit in the absence of the 580 resistor.

Answer 1

Answer:

1160 ohm

Explanation:

We are given that

R'=580 ohm

Current=3 I

We have to find the resistance of the circuit.

Let R be the resistance of circuit.

In parallel

$\frac{1}{R_{eq}}=\frac{1}{R_1}+\frac{1}{R_2}$

Using the formula

$\frac{1}{R_{eq}}=\frac{1}{580}+\frac{1}{R}=\frac{580+R}{580R}$

$R_{eq}=\frac{580R}{580+R}$

In parallel combination,Potential difference across each resistance remains same.

$V=IR$

Using the formula

$IR=3IR_{eq}$

$IR=3I\times \frac{580R}{580+R}$

$580+R=3\times 580=1740$

$R=1740-580=1160\Omega$