Question

An electron in a TV picture tube is accelerated through a potential difference of 10 kV before it hits the screen. What is the kinetic energy of the electron in electron volts?(1 eV = 1.6 ? 10 -19 J)

Answer 1

Answer:

10,000 eV

Explanation:

According to the law of conservation of energy, the kinetic energy gained by the electron is equal to its change in electric potential energy:

$K=\Delta U=q \Delta V$

where:

K is the kinetic energy of the electron

$q=1 e$ is the magnitude of the charge of the electron

$\Delta V$ is the potential difference through which the electron has been accelerated

For this electron in the TV, we have

$\Delta V=10 kV=10000 V$

Therefore, the kinetic energy of the electron in electronvolts is

$K=(1 e)(10000 V)=10000 eV$