1.

Two wires of same material and length have resistance 5 Omega and 10 Omega respectively. Find the ratio of radii of the two wires.

Answer»

Solution :`R = (rho l )/( A),`
`therefore R _(1) = (rho l )/( PI r _(1) ^(2))`
`and R _(2) = ( rho l )/( pi r _(2) ^(2))`
`(R _(2))/( R _(1)) = (r _(1) ^(2))/( r _(2) ^(2))`
`or (r_(1))/( r _(2)) = SQRT ((R _(2))/( R_(1)))= sqrt ((10)/( 5)) = (SQRT2 )/(1)`
`r _(1) :r _(2) = sqrt2 :1`


Discussion

No Comment Found

Related InterviewSolutions