A closed loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on…

A closed loop PQRS carrying a current is placed in a uniform magnetic field. If the magnetic forces on segments PS, SR and RQ are $F_1, F_2$ and $F_3$ respectively and are in the plane of the paper and along the directions shown, the force on the segment QP is
  1. $F_3-F_1+F_2$
  2. $F_3-F_1-F_2$
  3. $\sqrt{\left(F_3-F_1\right)^2+F_2^2}$
  4. $\sqrt{\left(F_3-F_1\right)^2-F_2^2}$

Solution

Since net force on current carrying loop in uniform magnetic field is zero therefore force on remaining segment will be equal and oppsoite to $\mathrm{F}$.

Asked in: NEET 2008 (Mains)

Practice more Magnetic Fields due to Electric Current questions on Aicharya