Wave Optics Practice Questions
JEE · Physics · 1456 free MCQs with instant results and detailed explanations.
1456
Total
323
Easy
664
Medium
469
Hard
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Topics in Wave Optics
Young's Double Slit
238
Diffraction
233
Polarisation
248
Brewster's Law
244
Huygens Principle
258
Interference
235
Sample Questions from Wave Optics
Here are 10 sample questions. Start a quiz to get randomized questions with scoring.
Q1
Easy
What does Huygens' principle state about wavefronts?
A.
Every point on a wavefront acts as a source of secondary waves.
B.
Light travels only in straight lines and does not bend.
C.
Wavefronts can only be spherical.
D.
All waves travel at the same speed in different mediums.
Show Answer & Explanation
Correct Answer: A
Huygens' principle states that every point on a wavefront can be considered a source of secondary wavelets, which spread out in all directions.
Q2
Easy
When a plane wavefront passes through a narrow slit, what type of wavefront is formed behind the slit?
A.
Cylindrical wavefront
B.
Spherical wavefront
C.
Planar wavefront
D.
Elliptical wavefront
Show Answer & Explanation
Correct Answer: B
When a plane wavefront passes through a narrow slit, each point in the slit acts as a source of secondary wavelets, resulting in a spherical wavefront behind the slit.
Q3
Easy
In the context of Huygens' principle, what is the 'secondary wavelet'?
A.
A wave that travels faster than light.
B.
A wave produced only at the edges of a wavefront.
C.
A wave emitted by each point on a wavefront.
D.
A reflection of the original wave.
Show Answer & Explanation
Correct Answer: C
A secondary wavelet is defined as the new wave that emanates from every point on a wavefront, according to Huygens' principle.
Q4
Medium
According to Huygens' principle, every point on a wavefront acts as a:
A.
source of secondary wavelets
B.
mirror reflecting light
C.
point of interference
D.
sink absorbing light
Show Answer & Explanation
Correct Answer: A
Huygens' principle states that every point on a wavefront serves as a source of secondary wavelets which spread out in all directions.
Q5
Medium
If a wavefront travels from a medium of refractive index 1 to another of refractive index 1.5, what is the speed of the wave in the new medium if the speed in the first medium is 3 x 10^8 m/s?
A.
2 x 10^8 m/s
B.
1.5 x 10^8 m/s
C.
2.5 x 10^8 m/s
D.
3.5 x 10^8 m/s
Show Answer & Explanation
Correct Answer: A
The speed of light in a medium is given by v = c/n, where c is the speed of light in vacuum and n is the refractive index. Thus, v = (3 x 10^8)/(1.5) = 2 x 10^8 m/s.
Q6
Medium
When light passes from air into water, the wavelength of light:
A.
Increases
B.
Decreases
C.
Remains the same
D.
Becomes zero
Show Answer & Explanation
Correct Answer: B
The wavelength of light decreases when it moves to a medium of higher refractive index, such as water from air, due to the formula λ' = λ/n.
Q7
Medium
In Huygens' principle, the new wavefront is formed by the:
A.
Points where secondary wavelets meet
B.
Maxima of the original wave
C.
Minima of the original wave
D.
Reflection of the original wavefront
Show Answer & Explanation
Correct Answer: A
According to Huygens' principle, the new wavefront is formed by the constructive interference of the secondary wavelets emanating from each point of the wavefront.
Q8
Hard
In a double-slit experiment, if the separation between the slits is increased, what happens to the fringe width?
A.
Increases
B.
Decreases
C.
Remains constant
D.
Becomes zero
Show Answer & Explanation
Correct Answer: B
Increasing the slit separation decreases the fringe width because fringe width is inversely proportional to the slit separation.
Q9
Hard
A wavefront is described by the function y(x, t) = A sin(kx - ωt). What does k represent in this equation?
A.
Angular frequency
B.
Wave number
C.
Phase velocity
D.
Amplitude
Show Answer & Explanation
Correct Answer: B
In the wave equation, k is the wave number which indicates the number of radians per unit distance.
Q10
Hard
When a wavefront passes through a small aperture, what phenomenon primarily explains the spreading of the wave?
A.
Reflection
B.
Refraction
C.
Diffraction
D.
Interference
Show Answer & Explanation
Correct Answer: C
Diffraction explains the spreading of waves when they encounter an obstacle or aperture, as per Huygens' Principle.
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Wave Optics — JEE Physics Practice Questions Online
This page contains 1456 practice MCQs for the chapter Wave Optics in JEE Physics. The questions are organized by difficulty — 323 easy, 664 medium, 469 hard — so you can choose the right level for your preparation.
Every question includes a detailed explanation to help you understand the concept, not just memorize answers. Take a timed quiz to simulate exam conditions, or practice at your own pace with no time limit. This chapter covers 6 topics, giving you comprehensive coverage of the entire chapter.