Assertion (A): The central fringe is bright or dark, it dependents on the initial phase difference between the two coherent sources.
Reason (R): The pattern and position of fringes always remains same even after the introduction of transparent medium in a path of one of the slit.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
Assertion (A) is true. The nature of the central fringe depends on the initial phase difference. Reason (R) is false. Introducing a transparent medium causes a path difference \((n-1)t\) and shifts the entire fringe pattern.
Assertion (A): Diffraction is a sure indication of wave nature.
Reason (R): Only transverse waves can be diffracted.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
Assertion (A) is true; diffraction is a characteristic property of all waves. Reason (R) is false; both transverse (e.g., light) and longitudinal (e.g., sound) waves can be diffracted.
Assertion (A): The best contrast of the interference pattern is obtained when the intensity of the emerging lights from the two slits of the Young’s experimental set-up are equal.
Reason (R): Intensity is proportional to the square of the amplitude.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
For best contrast in an interference pattern, the amplitudes of the interfering waves must be equal, implying equal intensities. Intensity \(I\) is proportional to the square of the amplitude \(A\), i.e., \(I \propto A^2\). Thus, equal intensities lead to maximum contrast.
Assertion (A): The central fringe is bright or dark, it depends on the initial phase difference between the two coherent sources.
Reason (R): The pattern and position of fringes always remains same even after the introduction of transparent medium in a path of one of the slit.
1. Both (A) & (R) are true and the (R) is the correct explanation of the (A)
2. Both (A) & (R) are true but the (R) is not the correct explanation of the (A)
3. (A) is true but (R) is false
4. Both (A) and (R) are false
View Answer
The central fringe's nature (bright/dark) depends on the initial phase difference. Introducing a transparent medium with refractive index \(n\) and thickness \(t\) in one path creates an additional path difference \((n-1)t\), shifting the entire fringe pattern. So, (R) is false.