What is the charge of anode ray? 

Positive 

The correct answer is option 1. Positive.

Anode rays, also known as positive ions or positive ion beams, are positively charged particles that are observed in certain types of gas discharge tubes, such as Crookes tubes or discharge tubes. These tubes consist of an anode (positively charged electrode) and a cathode (negatively charged electrode), as well as a gas at low pressure.

When a high voltage is applied across the electrodes of the discharge tube, electrons are emitted from the cathode and accelerated towards the anode. As these electrons collide with gas molecules in the tube, they can ionize the gas, creating positively charged ions.

These positively charged ions, known as anode rays, are then accelerated towards the cathode by the electric field within the tube. They travel in the direction opposite to that of the electron flow. Since these ions are positively charged, they are attracted towards the negatively charged cathode.

Anode rays can be observed as a luminescent glow or beam in the discharge tube, indicating the path of the positively charged ions. The properties of anode rays, such as their behavior in magnetic and electric fields, have been studied extensively and have contributed to our understanding of atomic and particle physics.

In summary, anode rays are positively charged ions that are observed in gas discharge tubes when a high voltage is applied. They move towards the cathode and can be used to study the behavior of charged particles in electric and magnetic fields.