Electron Specific Charge

Physics: AQA A Level, topic 12.1.3

Specific Charge of the Electron

Specific charge is a measure of charge per unit mass.

Specific charge

Specific charge is the charge per unit mass of a charged particle.
The equation for specific charge is specific charge = $\frac{Q}{m}$ .
The units for specific charge are Ckg^-1.

Specific charge of the electron

When talking about the electron, the equation becomes:
specific charge = $\frac{e}{m_e}$ .

Thomson's experiment

Thomson measured the specific charge of the electron before we knew the charge or the mass.
He performed an experiment which made use of an electric field and measured the deflection of the electrons.
The deflection allowed him to show that the electrons had a negative charge and a finite mass.

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