Question
Question: Take the particle in question number 52 electron projected with velocity \(v_{x} = 4 \times 10^{6}m^...
Take the particle in question number 52 electron projected with velocity vx=4×106ms−1. If electric field between the plates separated by 1 cm is 8.2×102NC−1, the the electron will strike the upper plate at (Take me=9.1×10−31kg)
A
2.14 cm
B
39 cm
C
1.23 cm
D
3.3 cm
Answer
3.3 cm
Explanation
Solution
: Given vx=4×106ms−1,d=1cm=1×10−2m
E=8.2×102NC−1
q=e=1.6×10−19C,me=9.1×10−31kg
The electron will strike the upper plate at its other end of x = L as soon as its deflection.
Or y=Zd=210−2m=5×10−3m
From (iii).
L=qE2mevx2y=1.6×10−19×8.2×1022×9.1×10−31×(4×106)2×5×10−3=3.33×10−2m
L=3.33cm
The electrons will strike the upper palte at its other end, if length of plate is 3.33 cm