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slader A long, straight wire carries a current of 5.20 AA. An electron is traveling in the vicinity of the wire. At the instant when the electron is 4.40 cmcm from the wire and traveling with a speed of 6.20×104 m/sm/s directly toward the wire, what is the magnitude of the force that the magnetic field of the current exerts on the electron?

Respuesta :

Answer:

[tex]2.34\cdot 10^{-19}N[/tex]

Explanation:

The strength of the magnetic field produced by a current-carrying wire is:

[tex]B=\frac{\mu_0 I}{2\pi r}[/tex]

where:

[tex]\mu_0[/tex] is the vacuum permeability

I is the current in the wire

r is the distance from the wire

In this case,

I = 5.20 A

r = 4.40 cm = 0.044 m

Therefore,

[tex]B=\frac{(4\pi \cdot 10^{-7})(5.20)}{2\pi (0.044)}=2.36\cdot 10^{-5} T[/tex]

The direction of the field is along concentric circles centered in the wire.

The force exerted by a magnetic field on a moving charged particle is

[tex]F=qvB sin \theta[/tex]

where

q is the charge

v is the velocity of the particle

[tex]\theta[/tex] is the direction between v and B

In this problem:

[tex]q=1.6\cdot 10^{-19}C[/tex] is the magnitude of the charge of the particle

[tex]v=6.20\cdot 10^4 m/s[/tex] is the velocity

[tex]\theta=90^{\circ}[/tex], because the electron is travelling towards the wire, so perpendicular to the lines of the magnetic field

Therefore, the magnitude of the force is:

[tex]F=(1.6\cdot 10^{-19})(2.36\cdot 10^{-5})(6.20\cdot 10^4)(sin 90^{\circ})=2.34\cdot 10^{-19}N[/tex]