Photons & Wave-Particle Duality (OCR A Level Physics)

Determine the S.I. base units for h.

base units = ....................................... [2]

The charged particles are accelerated through a potential difference V. The de Broglie wavelength λ of these particles is then determined by the researcher.

Each particle has mass m and charge q.

i)

Show that the de Broglie wavelength λ is given by the expression 

[2]

ii)

The researcher plots data points on a λ² against grid, as shown below.

percentage uncertainty = .................................... % [2]

[1]

[4]