Question

A 500 eV electron is fired directly towards a
plate having surface charge density -8.85 x 10-6 Cm
2. The distance from where the electron be projected
so that it just fails to strike the plate is
0.2 mm
0.33 mm
0.5 mm
1.21 mm​

Answer 1

Answer:

value of epsilon is 8.85 × 10^-12

sigma is the surface charge density.

Answer 2

Answer

.5mm

step by step explanation

concept: electric field on large plate will be E= σ/ε0*d

electron has energy of 500eV do it can cross maximum value of potential difference 500V to

Given : energy=500eV

potential difference we get =500V

surface charge density=8.85 x 10-6Cm

To find : distance from where the electron be projected

explanation:

E=σ/ε0*d

d=E*ε0/σ

d=500*8.85 x 10-12Cm/8.85 x 10-6Cm

d=0.5mm