Electron Emission

Step 1: Specific charge of electron.
The specific charge of an electron is the ratio of its charge to its mass. Mathematically, it is given by:

%5Ctext%7BSpecific%20charge%7D%20%3D%20%5Cfrac%7Be%7D%7Bm%7D

where

e%20%3D%201.6%20%5Ctimes%2010%5E%7B-19%7D%20%5C%2C%20%5Ctext%7BC%7D

is the charge of an electron, and

m%20%3D%209.11%20%5Ctimes%2010%5E%7B-31%7D%20%5C%2C%20%5Ctext%7Bkg%7D

is the mass of the electron.
Step 2: Calculation.
Substituting the values:

%5Cfrac%7B1.6%20%5Ctimes%2010%5E%7B-19%7D%7D%7B9.11%20%5Ctimes%2010%5E%7B-31%7D%7D%20%3D%201.8%20%5Ctimes%2010%5E%7B11%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

Step 3: Elimination.
- (A)

1.8%20%5Ctimes%2010%5E%7B-19%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

: Incorrect.
- (B)

1.67%20%5Ctimes%2010%5E%7B-19%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

: Incorrect.
- (C)

1.8%20%5Ctimes%2010%5E%7B11%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

: Correct.
- (D)

6.67%20%5Ctimes%2010%5E%7B11%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

: Incorrect.
Step 4: Conclusion.
Therefore, the specific charge of an electron is

1.8%20%5Ctimes%2010%5E%7B11%7D%20%5C%2C%20%5Ctext%7BC%2Fkg%7D

Chapter Questions
1 MCQs