The correct option is
B Stream of Electrons
The explanation for the correct option:
In the case of option (B)
- The cathode rays are deflected when electric and magnetic fields are applied to the cathode ray in the discharge tube, indicating that they are made up of charged particles.
- The deflection direction reveals that cathode rays are made up of negatively charged electrons.
- Therefore, cathode rays are streams of electrons.
Hence. option (B) is correct.
The explanation for incorrect options:
In the case of option (A)
- The energy that originates from a source and moves through space at the speed of light is referred to as radiation.
- This energy has wave-like characteristics and is accompanied by an electric field and a magnetic field.
Hence, option (A) is incorrect.
In the case of option (C)
- A stream of alpha particles is a positively charged nuclear particle identical to the nucleus of a helium atom that consists of two protons and two neutrons and is ejected at high speed in certain radioactive transformations.
- Cathode rays are generated through gases at low pressure and high voltage.
Hence, option (C) is incorrect.
In the case of option (D)
- Electromagnetic waves or EM waves are waves that are created as a result of vibrations between an electric field and a magnetic field.
- In other words, EM waves are composed of oscillating magnetic and electric fields.
Hence, option (D) is incorrect.