Physics 9702 · AS & A Level · SI units

SI units — practice question

A student performs a double-slit experiment with a laser that emits 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 placed $2.4\text{ m}$ from the slits. The separation across five bright fringes is measured to be $34\text{ mm}$. Determine the slit separation.

  • A$8.5 \times 10^{-3}\text{ m}$
  • B$2.4 \times 10^{-4}\text{ m}$
  • C$1.9 \times 10^{-4}\text{ m}$
  • D$4.8 \times 10^{-5}\text{ m}$

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