Gujarati
4.Moving Charges and Magnetism
normal

Two parallel wires in the plane of the paper are distance $X _0$ apart. A point charge is moving with speed $u$ between the wires in the same plane at a distance $X_1$ from one of the wires. When the wires carry current of magnitude $I$ in the same direction, the radius of curvature of the path of the point charge is $R_1$. In contrast, if the currents $I$ in the two wires have direction opposite to each other, the radius of curvature of the path is $R_2$.

If $\frac{x_0}{x_1}=3$, the value of $\frac{R_1}{R_2}$ is.

A

$3$

B

$4$

C

$5$

D

$6$

(IIT-2014)

Solution

$B _2=\frac{\mu_0 I }{2 \pi x _1}+\frac{\mu_0 I }{2 \pi\left( x – x _1\right)}$ (opposite )

$B_1=\frac{\mu_0 I }{2 \pi x _1}-\frac{\mu_0 I }{2 \pi\left( x – x _1\right)} \text { (same) }$

Case -$1$ When current is in the same direction

$B=B_1=\frac{3 \mu_0 I }{2 \pi x_0}-\frac{3 \mu_0 I }{4 \pi x _0}=\frac{3 \mu_0 I }{4 \pi x _0} $

$R _1=\frac{ mv }{ qB }$

Case-$2$ When current is in oposite direction

$B = B _2=\frac{9 \mu_0 I }{4 \pi x _0} $

$R _2=\frac{ mv }{ qB } $

$\frac{ R _1}{ R _2}=\frac{ B _2}{ B _1}=\frac{9}{3}=3$

Standard 12
Physics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.