Oscillations, Waves and Optics MCQ Quiz - Objective Question with Answer for Oscillations, Waves and Optics - Download Free PDF
Last updated on Jun 25, 2025
Latest Oscillations, Waves and Optics MCQ Objective Questions
Oscillations, Waves and Optics Question 1:
A narrow horizontal slit is illuminated by an extended sodium lamp. A thin Fresnel biprism with
its edge aligned perpendicular to the slit is positioned, as shown in the figure.
Given that the length of the slit is larger than the base of the biprism, the pattern of illumination on the screen is best described by
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 1 Detailed Solution
Solution:
Extended horizontal slit → Loss of spatial coherence along x
Multiple incoherent sources → Fringes washed out
Result on screen: Almost uniform illumination
Oscillations, Waves and Optics Question 2:
What will be the separation between the coherent sources formed by a bi-prism whose inclined faces makes an angle of 2° with its base, the slit source being 0.10 m away from the bi-prism (Given μ = 1.5)?
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 2 Detailed Solution
Calculation:
The separation between the coherent sources d formed by a bi-prism is given by the formula:
\(d = 2a(\mu - 1) \theta\)
where:
\(a = 0.10 m) (\text{distance of the slit from the bi-prism}),\\ \mu = 1.5 (\text{refractive index of the bi-prism}),\\ \theta = 2^\circ = \frac{2 \pi}{180} \, \text{radians} \)
Convert Angle to Radians:
\(\theta = 2^\circ = \frac{2 \times \pi}{180} = \frac{\pi}{90} \, \text{rad}\)
Apply the Formula:
\(d = 2 \times 0.10 \times (1.5 - 1) \times \frac{\pi}{90}\)
\(d = 2 \times 0.10 \times 0.5 \times \frac{3.1416}{90}\)
\(d = 0.20 \times 0.5 \times 0.0349\)
\(d = 0.00349 \, \text{m} = 3.49 \, \text{mm} \approx 3.5 \, \text{mm}\)
Thus, the separation between the coherent sources is approximately \( \boxed{3.5 \, \text{mm}} \)
Thus, option '3' is correct.
Oscillations, Waves and Optics Question 3:
The Lissajous figure may be a straight line if the phase difference is
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 3 Detailed Solution
Explanation:
The Lissajous figure represents the graph of a parametric equation involving two perpendicular harmonic oscillations:
\(x=Asin(\omega_xt+\delta)\)
\(y=Bsin(\omega_yt)\)
For the Lissajous figure to be a straight line, the two sinusoidal motions must be in perfect phase or anti-phase, meaning their phase difference \(\delta\) should be either 0 or π.
Thu, option '1' is correct.
Top Oscillations, Waves and Optics MCQ Objective Questions
Oscillations, Waves and Optics Question 4:
A narrow horizontal slit is illuminated by an extended sodium lamp. A thin Fresnel biprism with
its edge aligned perpendicular to the slit is positioned, as shown in the figure.
Given that the length of the slit is larger than the base of the biprism, the pattern of illumination on the screen is best described by
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 4 Detailed Solution
Solution:
Extended horizontal slit → Loss of spatial coherence along x
Multiple incoherent sources → Fringes washed out
Result on screen: Almost uniform illumination
Oscillations, Waves and Optics Question 5:
What will be the separation between the coherent sources formed by a bi-prism whose inclined faces makes an angle of 2° with its base, the slit source being 0.10 m away from the bi-prism (Given μ = 1.5)?
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 5 Detailed Solution
Calculation:
The separation between the coherent sources d formed by a bi-prism is given by the formula:
\(d = 2a(\mu - 1) \theta\)
where:
\(a = 0.10 m) (\text{distance of the slit from the bi-prism}),\\ \mu = 1.5 (\text{refractive index of the bi-prism}),\\ \theta = 2^\circ = \frac{2 \pi}{180} \, \text{radians} \)
Convert Angle to Radians:
\(\theta = 2^\circ = \frac{2 \times \pi}{180} = \frac{\pi}{90} \, \text{rad}\)
Apply the Formula:
\(d = 2 \times 0.10 \times (1.5 - 1) \times \frac{\pi}{90}\)
\(d = 2 \times 0.10 \times 0.5 \times \frac{3.1416}{90}\)
\(d = 0.20 \times 0.5 \times 0.0349\)
\(d = 0.00349 \, \text{m} = 3.49 \, \text{mm} \approx 3.5 \, \text{mm}\)
Thus, the separation between the coherent sources is approximately \( \boxed{3.5 \, \text{mm}} \)
Thus, option '3' is correct.
Oscillations, Waves and Optics Question 6:
The Lissajous figure may be a straight line if the phase difference is
Answer (Detailed Solution Below)
Oscillations, Waves and Optics Question 6 Detailed Solution
Explanation:
The Lissajous figure represents the graph of a parametric equation involving two perpendicular harmonic oscillations:
\(x=Asin(\omega_xt+\delta)\)
\(y=Bsin(\omega_yt)\)
For the Lissajous figure to be a straight line, the two sinusoidal motions must be in perfect phase or anti-phase, meaning their phase difference \(\delta\) should be either 0 or π.
Thu, option '1' is correct.