# How does a magnetic field affect a cathode ray?

## How does a magnetic field affect a cathode ray?

When an external electric field is applied, the cathode ray is deflected toward the positive pole. When a magnetic field is applied, the cathode ray is deflected from its normal straight path into a curved path. Millikan measured the fundamental charge of matter – the charge on an electron.

### Does cathode ray have magnetic field?

Summary. Cathode rays are deflected by a magnetic field. The rays are deflected away from a negatively charged electrical field and toward a positively charge field. The charge/mass ratio for the electron is 1.8 × 108 Coulombs/gram.

What is the purpose of the magnetic field in a cathode ray tube?

The magnetic field deflects the electrons according to the right hand rule. Deflection of Cathode Rays (electron beam) by an Electric Field – Turn on the power strip.

What is the relationship between electrons and a magnetic field?

The spinning of the electrons around the nucleus of an atom creates a tiny magnetic field. The electrons in most objects spin in random directions, and their magnetic forces cancel each other out. Magnets are different because the molecules in magnets are arranged so that their electrons spin in the same direction.

## Why do electrons have magnetic fields?

Magnetism is caused by the motion of electric charges. Each atom has electrons, particles that carry electric charges. Spinning like tops, the electrons circle the nucleus, or core, of an atom. Their movement generates an electric current and causes each electron to act like a microscopic magnet.

### What is charge of cathode rays?

Figure 14. Thomson’s apparatus for demonstrating that cathode rays have negative charge.

How are cathode rays affected by a magnetic field?

In a uniform magnetic field if the direction of cathode rays is perpendicular to the magnetic field then the electrons undergo uniform circular motion whereas if the rays are at an angle then the electrons travel on a helical path with uniform pitch. Hope you get the answer. There was an error loading more items.

How are magnetic plates used in cathode ray tubes?

Such plates can be used in a cathode ray tube to accelerate the electrons and also deflect them to write on a phosphor painted on the face of the tube as in early television. Magnetic fields can also be used to deflect electrons. The force exerted on the electron is given by the following equation that covers both electric and magnetic fields.

## How are electrons deflected in a cathode ray tube?

That rule describes how a charged particle (our electron) moving in a magnetic field will be deflected by that field at a right angle to both the field and to the direction of the particle. (As you apply that rule, remember that the electrons in the cathode ray are travelling opposite the flow of conventional current.)

### How are cathode rays similar to an electric current?

If the rays are a stream of negative electrons moving from left to right they are equivalent to a positive or conventional electric current in the reverse direction. It is clear, therefore, that if this assumption is true the rays behave like an ordinary electric current and obey Fleming’s left-hand rule (page 436).