The rest energy of an electron is

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(A) The rest mass energy of a particle is given by Einstein's mass-energy equivalence formula: $E = m_e c^2$.Here,the rest mass of an electron is $m_e

Vedclass · Accepted Answer

$510 \, keV$

Vedclass · Answer

(A) The rest mass energy of a particle is given by Einstein's mass-energy equivalence formula: $E = m_e c^2$.Here,the rest mass of an electron is $m_e = 9.109 	imes 10^{-31} \, kg$ and the speed of light is $c \approx 3 	imes 10^8 \, m/s$.Calculating the energy in Joules:$E = (9.109 	imes 10^{-31} \, kg) 	imes (3 	imes 10^8 \, m/s)^2 \approx 8.198 	imes 10^{-14} \, J$.To convert this energy into electron-volts $(eV)$,we divide by the charge of an electron $(1.602 	imes 10^{-19} \, C)$:$E = \frac{8.198 	imes 10^{-14} \, J}{1.602 	imes 10^{-19} \, J/eV} \approx 511,735 \, eV \approx 0.511 \, MeV = 511 \, keV$.Rounding to the standard value,the rest energy of an electron is approximately $510 \, keV$.

Similar Questions

The energy of a photon with a wavelength of $450 \, nm$ is ............

The energy of a photon of wavelength $\lambda$ is given by

The energy of a quantum of frequency $10^{15} \ Hz$ and $h = 6.6 \times 10^{-34} \ J \cdot s$ will be:

The velocity of a photon is proportional to (where $\nu$ is frequency):

$A$ sensor is exposed for time $t$ to a lamp of power $P$ placed at a distance $l$. The sensor has a circular opening that is $4d$ in diameter. Assuming all energy of the lamp is given off as light,the number of photons entering the sensor if the wavelength of light is $\lambda$ is (given $l >> d$):

Vedclass Test Series

Exam Paper Generator

Online Exam Module