Question

As the speed of the electrons increases, the measured value of charge to mass ratio (in the relativistic units):

• A. increases
• B. remains unchanged
• C. decreases
• D. first increases and then decreases

Answer 1

The correct option is C decreases

As the speed of the electrons increases, the measured value of charge to mass ratio (in the relativistic units) decreases. With an increase in the velocity, the mass of electron increases. The specific charge (e/m) is independent of the nature of gas and electrode used.

Note: The charge to mass ratio is called a specific charge.

Hence, the correct option is $\text{C}$