Physics 9702 · AS & A Level · SI units

SI units — practice question

A student performs a double-slit experiment with a laser that produces red light of wavelength $680\,\text{nm}$. The light falls normally on a double slit. The diagram shows part of the bright-fringe pattern seen on a screen $2.4\,\text{m}$ from the slits. The distance spanning five bright fringes is $34\,\text{mm}$. Determine the slit separation.

  • A$8.5\times10^{-3}\,\text{m}$
  • B$2.4\times10^{-4}\,\text{m}$
  • C$1.9\times10^{-4}\,\text{m}$
  • D$4.8\times10^{-5}\,\text{m}$

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI