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Question 1

describe the effect of charge moving in a magnetic feild. explain why this occurs

Answer 1

if a particle with charge q is moving with a velocity v, perpendicularly to a magnetic field of strength B, the particle will experience a magnetic force F given by:

F = pvBsinθ

the direction of the force is given by the right hand rule

Question 2

define the following:

• discharge tube
• anode
• cathode
• cathode rays
• straitions

Answer 2

discharge tube

an evacuated glass tube containing electrodes and used to investigate the effect of passing electricity through gasses at low pressure

anode

it is a possitively charged electrode by which the lectrons leave an electrical device.

cathode

the electron emitting electrode in an electron tube

cathode ray

cathode rays ae particles that travel from negative electrode (cathode) of an electric discharge tube

straitions

straitions are patterns formd in a gas at low pressure as an electrical discharge is passed through it

Question 3

explain why glass opposite the cathode glows green

Answer 3

When a cathode ray hits an object it emmits a green glow. the green glow occurs because when it collides it looses energy and the energy is lost in this glow.

Question 4

Describe the results of an experiment using a series of discharge tubes connected to a high voltage source whn pressure is gradually reduced

Answer 4

by reducing the amount of pressure in a discharge tube you create a vaccume. in a vacume there is less or no particle in it. therefore as a cathode ray passes through it will have less interference and the ray will go from showing straitions to a beam.

Question 5

what did the maltese cross shadow exeriment show?

Answer 5

this experiment shoed that the ray traveled in a straight line

Question 6

what did the electrical field tube experiment show?

Answer 6

that cathode rays were negativly charged

Question 7

what did the magnetic field bend ray experiment show?

Answer 7

it showed that cathode rays were affected by a magnetic field.

Question 8

what did the paddle wheel experiment show?

Answer 8

that cathode rays carry energy and momentum and therefore had mass.

Question 9

Recall evidence that suggested that cathode rays were waves when looking at cathode rays there a

Answer 9

when looking at cathode rays there are a few experiments that showed evidence for it being a wave.

• the maltese cross - showed that the ‘waves’ propigated in a straight line
• electric plates (Hertz) - the rays weren’t affected by the charge

Question 10

Recall evidence that suggested that cathode rays were particles.

Answer 10

when looking at cathode rays there are a few experiments that show evidence for them being a particle.

• paddle wheel experiment - showed it had momentum and energy and thterefore mass
• the magnetic field experiment - showed that they were negativly charged (waves cannot be)
• electric plates (Thomson) - showed rays actually were affected by an electric field