Answer: longitudinal waves.
- A transverse waves
- B electromagnetic waves
- C high-frequency waves
- D longitudinal waves
Correct answer: D. longitudinal waves
Explanation: Polarisation is possible only for transverse waves. Sound in air is longitudinal (vibration along the direction of travel), so it cannot be polarised.
Two coherent slits S₁ and S₂ act as secondary sources; at each point on the screen, the path difference between light from S₁ and S₂ determines whether the waves arrive in phase (bright fringe) or out of phase (dark fringe), producing the characteristic alternating fringe pattern.
Concept context
Huygens principle, Young's double slit, diffraction, polarization. Essential for JEE.