An electron moving at right angles to a 0.1 T magnetic field experiences an acceleration of 6 × 1015 m.s-2. What is the speed of the electron? How much does its speed change in 1 ns (10-9 s)?

Respuesta :

Explanation:

It is given that,

Magnetic field, B = 0.1 T

Acceleration, [tex]a=6\times 10^{15}\ m/s^2[/tex]

Charge on electron, [tex]q=1.6\times 10^{-19}\ C[/tex]    

Mass of electron, [tex]m=9.1\times 10^{-31}\ kg[/tex]    

(a) The force acting on the electron when it is accelerated is, F = ma

The force acting on the electron when it is in magnetic field, [tex]F=qvB\ sin\theta[/tex]

Here, [tex]\theta=90[/tex]

So, [tex]ma=qvB[/tex]

Where

v is the velocity of the electron

B is the magnetic field

[tex]v=\dfrac{ma}{qB}[/tex]

[tex]v=\dfrac{9.1\times 10^{-31}\ kg\times 6\times 10^{15}\ m/s^2}{1.6\times 10^{-19}\ C\times 0.1\ T}[/tex]

v = 341250  m/s

or

[tex]v=3.41\times 10^5\ m/s[/tex]

So, the speed of the electron is [tex]3.41\times 10^5\ m/s[/tex]

(b) In 1 ns, the speed of the electron remains the same as the force is perpendicular to the cross product of velocity and the magnetic field.