Question

the equivalent resistance of the resistance joined in parallel is 6/5 ohm.when one of the resistance wires is broken,the effective resistance becomes 2ohm. the resistance of the wire that got broken was

Answer 1

Answer:

Resistance of broken wire = 3 Ohm.

Step by step explanation:

It is given that the equivalent resistance for two parallel resistors $R_p=\frac{6}{5}$ Ohm.

Let $R_1$ be the resistance of the broken wire, and $R_2$ the resistance of the good wire.

It is also given that when one of the resistance wires is broken,the effective resistance becomes 2 ohm. Which means that $R_2=2\:Ohm$; since it is parallel with a broken wire (parallel with infinite resistance).

The formula for two parallel resistors is:

$R_p=\frac{R_1R_2}{R_1+R_2}\\\frac{6}{5}=\frac{R_1*2}{R_1+2}\\6(R_1+2)=10R_1\\4R_1=12\\R_1=3\:Ohm$