A wire carrying current I is tied between points P and Q and is in the shape of a circular arc of radius R due to a uniform magnetic field B (perpendicular to the plane of the paper, shown by xxx) in the vicinity of the wire. If the wire subtends an angle `2theta_(0)` at the centre of the circle (of which it forms an arc) then the tension in the wire is:

Options

A. `IBR`
B. `(IBR)/(sin theta_(0))`
C. `(IBR)/(2 sin theta_(0))`
D. `(IBR theta_(0))/(sin theta_(0))`

Answer

A

Explanation

Magnetic force on the circular arc
`F=I(2R sin theta_(0))B`
for the arc to be in equilibrium `F=2T sin theta_(0)`
`:.2Tsin theta_(0)=2IR sin theta_(0)B,T=IRB`