A velocity selector consists of electric and magnetic fields described by the expressions e with arrow = e k and b with arrow = b ĵ, with b = 22.0 mt. find the value of e such that a 850-ev electron moving in the negative x direction is undeflected.

Answer:

380.38 kV/m

Explanation:

We are given that

[tex]Electric field=E[/tex]

Magnetic field,B=22 mT=[tex]22\times 10^{-3} T[/tex]

Answer:380.38 kV/mExplanation:We are given that

[tex]Electric field=E[/tex]

Magnetic field,B=22 mT=[tex]22\times 10^{-3} T[/tex]

[tex] 1mT=10^{-3} T[/tex]

K.E=850e V=[tex]850\times 1.6\times 10^{-19} J[/tex]

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

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

Speed of electron,v=

[tex]\sqrt{\frac{2K.E}{m}[/tex][tex]v=\sqrt{\frac{2\times 850\times 1.6\times 10^{-19}}{9.1\times 10^{-31}}}[/tex]

[tex]v=17.29\times 10^6 m/s[/tex]

[tex]E=vB=17.29\times 10^6\times 22\times 10^{-3}=380.38\times 10^3 V/m=380.38KV/m[/tex]1 kV=[tex]10^3 V[/tex]