Explain how bright fringes arise in Young's double slit experiment

To answer this question, we need to think about 3 things: interference, phase and path difference

In the experiment, we have monochromatic light (from a laser) going through two slits and then bright and dark fringes appearing on the screen. (I will draw the experiment on the white board) 

What the monochromatic light means is that the light shining through the two slits act as two coherent sources of light (at the same frequency). In order for bright fringes to occur, the waves of light need to interfer constructively. This means that the displacement of the waves when they intefer with each other add together - they superimpose to make a larger amplitude ie the bright fringe. To interfer constructively like this, the waves must arrive together in phase and have a path difference which is a whole number of wavelengths (1 wavelength, 2 wavelengths etc)

HM
Answered by Harveer M. Physics tutor

3808 Views

See similar Physics A Level tutors

Related Physics A Level answers

All answers ▸

The speed of water moving through a turbine is 2.5 m/s. Show that the mass of water passing through an area of 500 metres squared in one second is about 1 x 10^6 kg (density of sea water = 1030 kg/m^3)


The Large Hadron Collider (LHC) of circumference 27km uses magnetic fields to accelerate a proton repeatedly in a circular path. Calculate the flux density of a uniform magnetic field required for the proton to travel at a tenth of the speed of light.


A guitar string 0.65m long vibrates with a first harmonic frequency of 280Hz. Mary measures 1m of the string and discovers that it weighs 8.0x10^-4 kg. What is the tension in the guitar string?


Explain the Doppler Shift Effect, and how it can be used to measure blood flow in the body.


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning