Electrons in an x-ray machine are accelerated from rest through a potential difference of 20,000 V.What is the kinetic energy of each of these electrons in eV?
A) 20 eV
B) 32 eV
C) 13 eV
D) 20 keV
E) 40 eV

Question

Electrons in an x-ray machine are accelerated from rest through a potential difference of 20,000 V.What is the kinetic energy of each of these electrons in eV?
A) 20 eV
B) 32 eV
C) 13 eV
D) 20 keV
E) ​40 eV

Quizplus · Accepted Answer

The kinetic energy gained by each electron can be calculated using the formula, K.E. = eV, where e is the charge of an electron and V is the potential difference. Therefore, K.E. = (1.6 × 10^-19 C) × 20,000 V = 3.2 × 10^-15 J. Now, 1 eV is defined as the amount of energy gained by an electron when accelerated through a potential difference of 1 V. Therefore, K.E. in eV = (3.2 × 10^-15 J) / (1.6 × 10^-19 J/eV) = 20,000 eV = 20 keV. Hence, the correct choice is D, which is 20 keV.

Electrons in an X-Ray Machine Are Accelerated from Rest Through