Moving Charges and Magnetism - Result Question 67

68.

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

[2008]

(a) $F_3-F_1-F_2$

(b) $\sqrt{(F_3-F_1)^{2}+F_2^{2}}$

(c) $\sqrt{(F_3-F_1)^{2}-F_2^{2}}$

(d) $F_3-F_1+F_2$

Show Answer

Answer:

Correct Answer: 68. (b)

Solution:

  1. (b) According to the figure the magnitude of force on the segment $QM$ is $F_3-F_1$ and $PM$ is $F_2$.

Therefore, the magnitude of the force on

segment $PQ$ is $\sqrt{(F_3-F_1)^{2}+F_2^{2}}$