An electron enters the region between two horizontal plates with an initial velo
ID: 1547808 • Letter: A
Question
An electron enters the region between two horizontal plates with an initial velocity of 2 x 106i m/s midway between two horizontal plates; see Fig. 23.40. The plates are 4cm long and 1.6cm apart. What is the magnitude of the maximum vertical electric field such that the electron does not strike either plate?
DUU come come to rest? 0. D An electron enters the region between two horizontal plates with an initial velocity of 2 x 106i m/s midway be- tween two horizontal plates; see Fig. 23.40. The plates are 4 cm long and 1.6 cm apart. What is the magnitude of the maximum vertical electric field such that the electron does not strike either plate? 4 cm 1.6 cm FIGURE 23.40 Exercise 30.Explanation / Answer
time = 0.04 / 2 X 106
= 20 n.sec
displacement S = 1.6 / 2 = 0.8 cm
S = ut + 1/2 at2
a = 2 s / t2
a = 2 X 0.8 X 10-2 / ( 20 X 10-9 )2
= 4 X 1013 m/sec2
the electric field due to electron
F = e E
m a = e E
E = m a / E
= 9.1 X 10-31 X 4 X 1013 / 1.6 X 10-9
E = 227.5 N/C