Question 1:
easySpherical wavefronts shown in fig, strike a plane mirror. Reflected wavefronts will be as shown in:
Practice NEET Huygen's Principal Questions
Question 2:
easyLight waves travel in vaccum along the y-axis. Which of the following may represent the wavefront?
Wavefronts are surfaces of constant phase which are perpendicular to the direction of propagation. Since propagation is along the y-axis, the wavefront must be parallel to the x-z plane, represented by \(y =\text{ constant}\).
Question 3:
easyAssertion (A): Huygens’s principle can explain converging nature of convex lens.
Reason (R): Snell’s law can be derived from Huygens’s principle.
Assertion (A) is true. Huygens' principle, through its explanation of wavefront changes, can explain how a convex lens converges light.
Reason (R) is true. Snell's law of refraction, which governs how light behaves at interfaces, can be derived directly from Huygens' principle.
Reason (R) explains a fundamental principle (Snell's Law) that underpins the behavior of lenses, thus it correctly explains (A).
Question 4:
easyAssertion (A): If incident wavefront is plane, then after reflection or refraction the emerging wave front also must be plane.
Reason (R): Wavefronts are in the direction of energy propagation by light.
Assertion (A) is true: A plane wavefront remains plane after reflection or refraction from plane/spherical surfaces. Reason (R) is false: Wavefronts are surfaces of constant phase and are perpendicular to the direction of energy propagation (rays). Hence, (A) is true, but (R) is false.
Question 5:
easyAssertion (A): Light is a wave phenomenon.
Reason (R): Light requires a material medium for its propagation.
Light is an electromagnetic wave and can travel through vacuum, so it does not require a material medium for propagation. Thus, Assertion (A) is true but Reason (R) is false.
Question 6:
easyIf a plane wave front is incident on a convex lens then the emerging wavefront will be
A convex lens focuses parallel rays (plane wavefront) to a single point, meaning the emerging wavefront converges as a spherical wavefront.
Question 7:
moderateWhich one of the following phenomena is not explained by Huygen’s construction of wavefront?
(1988)
Huygen's wave theory of light successfully explained phenomena like reflection, refraction, interference, and diffraction. However, it could not explain the origin of spectra, which requires quantum mechanics and the particle nature of light.