Discovery Of e-

Question 1

What are cathode rays composed of?

Answer 1

Negatively charged particles called electrons

Cathode rays are streams of electrons emitted from the cathode in a vacuum tube.

Question 2

What happens to cathode rays in the presence of electrical or magnetic fields?

Answer 2

They exhibit behavior that deviates from straight-line motion

This behavior is due to the forces exerted by the fields on the charged particles.

Question 3

What is the effect of cathode rays on fluorescent materials?

Answer 3

They cause the materials to glow

This glow is utilized in television screens to produce images.

Question 4

What did Michael Faraday demonstrate in the 1830s regarding electricity?

Answer 4

Electricity causes chemical reactions at electrodes

Faraday’s experiments showed the relationship between electricity and chemical changes.

Question 5

In what type of tube are cathode rays observed?

Answer 5

Cathode ray tubes

These tubes are partially evacuated and contain electrodes.

Question 6

What occurs when high voltage is applied across electrodes in a cathode ray tube?

Answer 6

Current starts flowing through a stream of particles

This flow is due to the movement of electrons towards the anode.

Question 7

What did J.J. Thomson discover in relation to cathode rays?

Answer 7

The particle nature of cathode rays

Thomson’s work led to the identification of electrons as fundamental particles.

Question 8

What is the relationship between charged particles in terms of attraction?

Answer 8

Unlike charges attract each other

This principle is fundamental to the behavior of charged particles in electric and magnetic fields.

Question 9

Fill in the blank: Cathode rays start from the ______.

Answer 9

cathode

Question 10

What is the effect of cathode rays on the anode?

Answer 10

They strike the anode, sometimes creating holes

This interaction can lead to physical changes in the anode material.

Question 11

What type of pressure is required for gas discharge to be observed in cathode ray tubes?

Answer 11

Very low pressures

High voltage and low pressure conditions are critical for the visibility of cathode ray phenomena.

Question 12

True or False: Cathode rays travel in straight lines when there is no external field present.

Answer 12

True

Question 13

What does the glow on a television screen result from?

Answer 13

Cathode rays hitting phosphorescent materials

This interaction produces visible light on the screen.