Question

In e/m experiment we assume nature of electrons as
a. Wave
b. Particle
c. Photon
d. Both A and B

Answer 1

Hint: The e/m experiment by J.J. Thomson was carried out before the discovery of electrons as a wave and a particle, till then the electrons were considered as particles. Electrons were considered as particles because they would collide with others.

Complete step by step answer:
In the nineteenth century, J.J. Thomson proposed his atomic model and discovered the electrons as subatomic particles. He considered electrons as negatively charged particles that had a very less mass. After the discovery of electrons, he performed an experiment to calculate the e/m ratio i.e., the ratio of the charge of an electron to the mass of the electron.
The mass of an electron found out was $m = 9.10938356 \times {10^{ - 31}}kg$
And the magnitude of charge of the electron $e = 1.602 \times {10^{ - 19}}C$
The charge to mass ratio of the electron came out to be $e/m = 1.758820 \times {10^{11}}C/kg$

J.J. Thomson performed an experiment with cathode rays in the effect of magnetic and electric fields and proved that the cathode rays are actually made up of particles by which he could find out the e/m ratio.
After this experiment De Broglie proposed the wave nature of electrons for which he won a Nobel Prize in 1929. After that electrons were considered like both particles and waves as they collide with other particles and also possess diffraction like light.

Hence, the correct answer is option (B).

Note: The question asks about the period when the electrons were considered as particles only. Later on, the electrons were considered to possess wave-particle dual nature. Electrons when passed through a thin metal film produced an interference pattern just like a wave.