What do you understand by rest mass of the electron ? What is its value on the unified scale ? How is the mass of the electron related to its velocity ? What will be the mass of the electron if it travels with velocity equal to the velocity of light ?

What do you understand by rest mass of the electron ? What is its valu

1.	What do you understand by rest mass of the electron ? What is its value on the unified scale ? How is the mass of the electron related to its velocity ? What will be the mass of the electron if it travels with velocity equal to the velocity of light ?
Answer» Solution :Rest mass of the electron is the mass of the electron when it is moving with a velocity much less than the velocity of light. Its value `= 9.1095 xx 10^(-31)kg or 0.0005486u`. When the electron is moving with velocity v, its mass is given by : `m = (m_("rest"))/(SQRT(1 - ((v)/(c))^(2)))` where c is the velocity of light. Thus, when electron is moving with the velocity of light so that v = c, its mass is infinite.