CIE A Level Physics复习笔记22.1.5 The Work Function
Photoelectric Emission The work function Φ, or threshold energy, of a material is defined as: The minimum energy required to release a photoelectron from the surface of a material Consider the elec...
CIE A Level Physics复习笔记22.1.4 Threshold Frequency
Threshold Frequency & Wavelength The concept of a threshold frequency is required in order to explain why a low frequency source, such as a filament lamp, was unable to liberate any electrons i...
CIE A Level Physics复习笔记22.1.3 The Photoelectric Effect: Basics
The Photoelectric Effect: Basics The photoelectric effect is the phenomena in which electrons are emitted from the surface of a metal upon the absorption of electromagnetic radiation Electrons remo...
CIE A Level Physics复习笔记22.1.2 The Electronvolt
The Electronvolt The electronvolt is a unit which is commonly used to express very small energies This is because quantum energies tend to be much smaller than 1 Joule The electronvolt is derived f...
CIE A Level Physics复习笔记22.1.1 The Photon
The Particle Nature of Light In classical wave theory, electromagnetic (EM) radiation is assumed to behave as a wave This is demonstrated by the fact EM radiation exhibits phenomena such as diffrac...
CIE A Level Physics复习笔记21.1.5 Smoothing
Smoothing In rectification, to produce a steady direct current or voltage from an alternating current or voltage, a smoothing capacitor is necessary Smoothing is defined as: The reduction in the ...
CIE A Level Physics复习笔记21.1.4 Rectification
Rectification Graphs Rectification is defined as: The process of converting alternating current and voltage into direct current and voltage Rectification is used in electronic equipment which req...
CIE A Level Physics复习笔记21.1.3 Mean Power
Mean Power In mains electricity, current and voltage are varying all the time This also means the power varies constantly, recall the equations for power: Where: I = direct current (A) V = direct...
CIE A Level Physics复习笔记21.1.2 Root-Mean-Square Current & Voltage
Root-Mean-Square Current & Voltage Root-mean-square (r.m.s) values of current, or voltage, are a useful way of comparing a.c current, or voltage, to its equivalent direct current, or voltage Th...
