Two superposing waves are represented by the following equations: 
\({\mathrm{y}_1=5 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}), \mathrm{y}_2=10 \sin 2 \pi(10 \mathrm{t}-0.1 \mathrm{x}).}\)
Ratio of intensities $\frac{{\mathrm{I}}_{\max }}{{\mathrm{I}}_{\min }}$ will be:

1. 1
2. 9
3. 4
​​​​​​​4. 16

In Young's double-slit experiment, the ratio of intensities of bright and dark fringes is 9. This means that:

A single slit of width 0.1 mm is illuminated by a parallel beam of light of wavelength 6000 $\stackrel{0}{\mathrm{A}}$ and diffraction bands are observed on a screen 0.5 m from the slit. The distance of the third dark band from the central bright band is:

1. 3 mm

2. 9 mm

3. 4.5 mm

4. 1.5 mm

In Young's double-slit experiment the light emitted from the source has $\lambda$ = 6.5 × 10^–7 m and the distance between the two slits is 1 mm. The distance between the screen and slits is 1 metre. Distance between third dark and fifth bright fringe will be:

1. 3.2 mm 

2. 1.63 mm 

3. 0.585 mm 

4. 2.31 mm

In Young's double-slit experiment, the slit separation is doubled. This results in:

Two polaroids are kept crossed to each other. Now one of them is rotated through an angle of $45°$. The percentage of incident light now transmitted through the system is:

1.  15%

2.  25%

3.  50%

4.  60%

Light travels faster in the air than in glass. This is in accordance with:

The distance of the moon from the earth is $3.8\times {10}^5 km$. The eye is most sensitive to light of wavelength 5500 Å. The minimum separation between two points on the moon that can be resolved by a 500 cm telescope will be:

1. 51 m                         

2. 60 m

3. 70 m                         

4. All the above

The ratio of resolving powers of an optical microscope for two wavelengths ${\lambda }_1=4000 \stackrel{o}{A } and {\lambda }_2=6000 \stackrel{o}{A}$ is:

1. 8:27

2. 9:4

3. 3:2

4. 16:81

A beam of light AO is incident on a glass slab (μ = 1.54) in a direction as shown in the figure. The reflected ray OB is passed through a Nicol prism. On viewing through a Nicole prism, we find on rotating the prism that: