The ressultant force on the current looop PQRS due to a long current carrying conductor will be

Options

A. `1.8xx10^(-4)N`
B. `5xx10^(-4)N`
C. `10^(-4)N`
D. `3.6xx10^(-4)N`

Answer

B

Explanation

The effective force is only on PQ and RS .
The force on PQ is attractive and ON RS it is repulsive . Force between two current carrying conductors is `F_(1)` betweeen AB and PQ `(mu_(0)i_(a)i_(b))/(2pid)`L repulsive force
and `F_(2)` between AB and RS `=(mu_(0)i_(a)i_(b)*L)/(2pid)` repulsive.
`thereforeF_(1)-F_(2)=((2mu_(0))/(4pi))(20xx20xx0.15)/(0.02)-(2mu_(0))/(4pi)(20xx20xx0.15)/(0.12)`
`rArrF_("resultant")=2xx(mu_(0))/(4pi)xx20xx20xx0.15*{(100)/(2)-(100)/(12)}`
`=2xx10^(-7)xx400xx(0.15xx500)/(12)`
`rArrF=55xx10^(-4)N`.