Question

A wire of 6m length has resistance 15 ohm is cut into 3 equal parts and connected in parallel and to 10 volt battery find net resistance in the circuit and current flowing through each resistor.​

Answer 1

Answer:

By unitary method,

6m long wire --> 15 ohm resistance

1m long wire --> 15/6 ohm resistance

So, when wire is cut into 3 equal parts, the 6m long wire gets divided into 3 equal parts of 2m each and hence,

                     2m long wire --> (15/6)x2 ohm resistance = 5 ohm

So, when the three 2m wires are connected in parallel to a 10V battery,

  Net resistance, 1/R = 1/5 + 1/5 + 1/5 = 3/5

                          =>  R = 5/3 Ω

Now, since potential difference is same across all three resistors(as they are connected in parallel),

So, Current through each resistor will be = V/R

                                                                       = 10/(5/3)

                                                                       = 30/5

                                                                       = 6 A