Which among the following is not a category of 'Fluctuation Noise' ?

Which among the following is not a category of 'Fluctuation Noise' ?

a. Shot Noise
b. Thermal Noise
c. Internal Noise
d. Flicker Noise

Correct Answer : d. Flicker Noise

Explanation :

Imperfections in cathode surface of electron tubes & surfaces around the junction of semiconductor devices results in the generation of flicker noise. Besides these, Shot noise & Thermal noise are the types of fluctuation noise whose another name is supposed to be 'Internal Noise'.