Question

A circular wire $\text{ABC}$ and a straight conductor $\text{ADC}$ are assumed to be a carrying current $i$ and are kept in the magnetic field $B$ then considering points $\text{A}$ and $\text{C}$ as shown in the figure.

• A. Force on $\text{ABC}$ is more than that on $\text{ADC}$
• B. Force on $\text{ABC}$ is less than that on $\text{ADC}$
• C. Force on $\text{ABC}$ is equal to that on $\text{ADC}$
• D. Cannot be predicted with the given data

Answer 1

The correct option is C Force on $\text{ABC}$ is equal to that on $\text{ADC}$

Force on a conductor placed in an external magnetic field is given by $$F=BIl\sin \theta$$ Here, $l$ is the length of the conductor
and for both conductors, $\theta ={90}^{\circ }$ , So $\sin \theta =1$.

The effective length of the conductor $\text{ABC}$ is equal to the length of conductor $\text{ADC}$.

So, force on conductor $\text{ABC}$ will be equal to the force on conductor $\text{ADC}$.

Hence, option (a) is the correct answer.