DP Physics (last assessment 2024)

Question 20N.2.HL.TZ0.10a

[Maximum mark: 1]

20N.2.HL.TZ0.10a

The de Broglie wavelength $λ$ of a particle accelerated close to the speed of light is approximately

$λ \approx \frac{h c}{E}$

where $E$ is the energy of the particle.
A beam of electrons of energy $4.2 \times 10^{8} eV$ is produced in an accelerator.

(a)

Show that the wavelength of an electron in the beam is about $3 \times 10^{- 15} m$ .

[1]

Markscheme

$λ = \frac{6.63 \times 10^{- 34} \times 3 \times 10^{8}}{1.60 \times 10^{- 19} \times 4.2 \times 10^{8}}$ OR $= 2.96 \times 10^{- 15} « m »$ ✓

Answer to at least $2$ s.f. (i.e. 3.0)

Examiners report

An easy calculation with only one energy conversion to consider and a 'show' answer to help.

Syllabus sections