A)Calculate the voltage required to accelerate a beam of electrons initially at
ID: 1418870 • Letter: A
Question
A)Calculate the voltage required to accelerate a beam of electrons initially at rest if they have a kinetic energy of 2.9 eV
B)Calculate their speed if they have a kinetic energy of 2.9
eV
C)Calculate the voltage required to accelerate a beam of electrons initially at rest if they have a kinetic energy of 3.5
keV .
D)Calculate their speed if they have a kinetic energy of 3.5
keV .
E)Calculate the voltage required to accelerate a beam of electrons initially at rest if they have a kinetic energy of 3.5×1016
J
F)Calculate their speed if they have a kinetic energy of 3.5×1016
J
Explanation / Answer
A. Using work energy theoram
W = dKE
also
W = q*V
given dKE = 2.9 eV
q*V = 2.9 eV
e*V = 2.9 eV
V = 2.9 eV/e = 2.9 V
Voltage required = 2.9 V
B.
KE = 0.5*m*v^2
2.9*eV = 0.5*m*v^2
v = sqrt (2*2.9 eV/m)
v = sqrt (2*2.9*1.6*10^-19/(9.1*10^-31))
v = 1.009*10^6 m/sec
C.
q*V = KE
e*V = 3.5*k eV = 3500 eV
Voltage required = 3500 V
D.
v = sqrt (2*KE/m)
v = sqrt (2*3500*1.6*10^-19/(9.1*10^-31))
v = 35.08*10^6 m/sec