SPM FORM 5 PHYSICS



Cathode Ray Oscilloscope (C.R.O)

To understand this topic, u must understand the following definition:
Themionic emission: - the release of electrons from a heated metal cathode
From the process of thermionic emission, we can produce cathode ray... By the way, what is chathode ray??
Cathode ray defined as a beam of electrons moving at high speed in a vacuum.
This cathode ray concept is widely used in making TV. In SPM, we apply its concept in understanding the uses of Cathode Ray Oscilloscope.

Before applying CRO, u must understand the properties of the cathode ray itself. Make sure u hafal all those properties such as:
-moving in straight line
-negatively charged
-deflected by electric & magnetic field and etc.

Once u've understood & investigated all the properties..then lets have a look at the structure of the device called CRO:
Like it or not this chapter requires u to hafal all those structure of CRO. Besides that, u need also to memorise their function as they might be asked in the exam.
Then, u must understand the working principle of CRO and how to calculate the voltage + frequency of a waveform.

To calculate the voltage & frequency, u must understand to use 2 important button in CRO, i.e
'Y-Gain' & 'Time base'