Question

A wire of resistance 9 ohm is elongated such that its length is doubled now this elongated wire is bent into a regular hexagon ABCDEF R effective blw A and c is....pls answer as quickly as possible

Answer 1

equivalent Resistance b/w A and C = 8 ohm

We know,

R = resistivity * (length of wire / CSA )

it can be written as,

R = resistivity * ( L^2 / V )

...... where, L - length, V - volume of the wire

volume and resistivity are constant.

so, after elongation resistance of the wire:

= 9 * ( 2 / 1 )^2

= 36 ohm

Resistance of each arm of Hexagon = 36/6 = 6 ohm

now, resist. b/w A & C = 12*24/(12+24) = 8 ohm