Chapter 09: Vectors and Equilibrium

This is a ninth chapter of the book Physics 11 published by Punjab Curriculum and Textbook Board, Lahore, Pakistan.

After studying this chapter the students will be able to:

• Understand the concept of wavefront.
• State Huygen's principle.
• Use Huygen's principle to explain linear superposition of light.
• Understand interference of light.
• Describe Young's double slit experiment and the evidence its provided to support the wave theory of light.
• Recognize and express colour patterns in than films.
• Describe the formation of Newton's rings.
• Understand the working of Michelson's interferometer and its uses.
• Explain the meaning of the term diffraction.
• Describe diffraction at a single slit.
• Drive the equation for angular position of first minimum.
• Drive the equation $d \sin \theta = m \lambda$.
• Carry out calculations using the diffraction grating formula.
• Describe the phenomenon of diffraction of X-rays through crystals.
• Appreciate the use of diffraction of X-rays by crystals.
• Understand polarization as a phenomenon associated with transverse waves.
• Recognize and express that polarization is produced by a Polaroid.
• Understand the effect or rotation of Polaroid on polarization..
• Understand how plane polarized light is produced and detected..