Question

What are canal rays?
(A). Positively charged radiations.
(B). Positively charged electrons.
(C). Negatively charged electrons.
(D). Negatively charged radiations.

Answer 1

Hint: The canal rays are a beam of rays that move in a direction towards the cathode which is a negatively charged electrode and away from the anode which is a positively charged electrode in a discharged tube when it is under high voltage and low pressure.

Complete step-by-step solution -

Canal rays also known as anode rays are positively charged radiations that are observed under very low pressure and high voltage in a discharged tube. Hence option A is correct. Let us understand more about these rays.

• • Canal rays depend upon the gas present in the discharged tube. Canal rays cannot exist without any gas present in the discharged tube.

• • This is because these rays are composed of positively charged ions that are formed due to the ionisation of the gas present in the tube.

• • A high voltage is required for the formation of canal rays. This is because a high voltage in the discharged tube will ionize the gas present in it. And these ionised gas constitutes the canal rays.

• • A very low pressure inside the discharged tube is required to allow the positively charged ions to move freely.

• • The discharged tube is made up of glass and inside it, two metal pieces are present which are oppositely charged and have high voltage among them.

• • When the high voltage is applied in the tube, an electric field is created and it accelerates the electrically charged ions which are present in the gas.

• • These charged ions begin to move and collide with the neutral atoms of the gas and knocks off the electrons making more positive ions.

• • These positive ions in turn knocks more electrons and this continues in a chain reaction and forms a beam of positive ions. In this way, canal rays are created.

• • The discharged tube is made up of glass and inside it, two metal pieces are present which are oppositely charged and have high voltage among them.

Note: Don’t confuse canal rays with cathode rays. Canal rays and cathode rays are the opposite of each other. The cathode rays are a beam of electrons that travel away from the cathode towards the anode while canal rays are a beam of positively charged ions that move in the exact opposite direction.