Higher Physics

Particles and Waves - Activity 1A

Interference of microwaves

Aim - To investigate a microwave interference pattern and to find the wavelength of microwaves.     Instructions
The transmitter produces microwaves which are split into two coherent sources at the double slit.  An interference pattern is produced and the receiver can be moved to detect areas of constructive and destructive interference.
  • Click on the up arrow to move the microwave receiver up. Click on the down arrow to move the receiver down.
  • Move the receiver up to find the position of the first order maximum.
  • Click and drag the rule to position it so that the end of the rule is in the centre of one of the slits.
  • Click on the curved arrows to rotate the rule.
  • Measure the distance from the centre of the slit to the point B on the receiver.
  • Move the rule and measure the distance from the second slit to the receiver.
  • Move the receiver up and find the positions of the 2nd and 3rd maxima. 
  • Repeat the measurements of S1 B and S2 B.  Complete the table below and calculate the wavelength of the microwaves.
Order (max) S1 B (cm) S2 B (cm) Path difference Wavelength (cm)
1st        
2nd        
3rd        
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