Question 1 :
In the experiment of diffraction at a single slit, if the slit width is decreased, the width of the central maximum

Question 2 :
In Youngs experiment, monochromatic light is used to illuminate the two slits <img style='object-fit:contain' width=9 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea297208ab67a08eba55c8d"> and <img style='object-fit:contain' width=10 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea297a701a30b5955496f96"> . Interference fringes are observed on a screen placed in front of the slits. Now if a thin glass plate is placed normally in the path of the beam coming from the slit<br> <img style='object-fit:contain' width=138 height=131 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea298718ab67a08eba55f58">

Question 4 :
In Youngs double slit experiment, a third slit is made in between the double slits. Then

Question 5 :
It is believed that the universe is expanding and hence the distant stars are receding from us. Light from such a star will show

Question 6 :
When the wavelength of light coming from a distant star is measured it is found shifted towards red. Then the conclusion is

Question 8 :
A parallel beam of fast moving electrons is incident normally on a narrow slit. A screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statement is correct

Question 9 :
In the Youngs double slit experiment, the interference pattern is found to have an intensity ratio between bright and dark fringes as 9. This implies that

Question 10 :
Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays, then the pattern will reveal that

Question 11 :
An interference pattern was made by using red light. If the red light changes with blue light, the fringes will become

Question 12 :
Interference was observed in interference chamber when air was present, now the chamber is evacuated and if the same light is used, a careful observer will see

Question 13 :
A parallel beam of fast moving electrons is incident normally on a narrow slit. A screen is placed at a large distance from the slit. If the speed of the electrons is increased, which of the following statement is correct?

Question 15 :
Consider the following statements <img style='object-fit:contain' width=9 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea297208ab67a08eba55c8d"> and <img style='object-fit:contain' width=10 height=20 src="https://storage.googleapis.com/teachmint/question_assets/NEET/5ea297a701a30b5955496f96"> and identify the correct answer<br> A. Polarised light can be used to study the helical surface of nucleic acids<br> B. Optics axis is a direction and not any particular line in the crystal

Question 16 :
The sun is rotating about its own axis. The spectral lines emitted from the two ends of its equator, for an observer on the earth, will show

Question 17 :
A telescope has an objective of focal length 50 cm and an eye piece of focal length 5 cm. The least distance of distinct vision is 25 cm. The telescope is focused for distinct vision on a scale 200 cm away. The separation between the objective and the eye-piece is[Kerala PET 2002]

Question 18 :
The diffraction effects in a microscopic specimen become important when the separation between two points is

Question 19 :
Image formed by a plane mirror is<br/>a) of same size as that of object<br/>b) at the same distance behind the mirror as the object in front<br/>c)&#160;erect,&#160;virtual<br/>Mark the correct statements:<br/>

Question 20 :
A beam of light of {tex} \lambda = 600 \mathrm { \mu m } {/tex} from a distant source falls on a single slit {tex}1 \mathrm { mm } {/tex} wide and the resulting diffraction pattern is observed on a screen {tex} 2\mathrm { m } {/tex} away. The distance between first dark fringes on either side of the central bright fringe is

Question 21 :
Figure shows two coherent sources {tex} \mathrm { S } _ { 1 } {/tex} and {tex} \mathrm { S } _ { 2 } {/tex} vibrating in same phase. {tex} \mathrm { AB } {/tex} is an irregular wire lying at a far distance from the sources {tex} \mathrm { S } _ { 1 } {/tex} and {tex} \mathrm { S } _ { 2 } {/tex} . Let {tex} \frac { \lambda } { \mathrm { d } } = 10 ^ { - 3 } {/tex} and {tex} \angle \mathrm { BOA } = 0.06 ^ { \circ } {/tex} . How many bright spots will be seen on the wire, including points {tex} \mathrm { A } {/tex} and {tex} \mathrm { B } {/tex} ?<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f07de5db655bbf10a673"><br>

Question 22 :
For reflection from air to glass , the value if incident angle for which the reflected light is totally polarised (refractive index = n)

Question 23 :
A convex lens of crown glass ({tex}n{/tex}=1.525) will behave as a divergent lens if immersed in [CPMT 1984]

Question 24 :
The figure shows the interference pattern obtained in a double-slit experiment using light of wavelength {tex}600 \mathrm {nm}{/tex}. {tex} 1,2 {/tex} {tex} 3,4 {/tex} and {tex}5{/tex} are marked on five fringes. The third order bright fringe is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f0bee5db655bbf10a710"><br>

Question 25 :
In a Young's double slit experiment, the intensity at a point where the path difference {tex}\frac{\lambda}{6}{/tex}({tex}\lambda{/tex} - is wavelength of the light) is {tex}I{/tex}. If {tex}I_{0}{/tex} denotes the maximum intensity, then {tex}\frac{I}{I_{0}}{/tex} is equal to

Question 26 :
Which statement is wrong&#160;from the following for the reflection by plane mirror?

Question 27 :
The dispersive powers of crown and flint glasses are 0.03 and 0.05 respectively. The refractive indices for yellow light for these glasses are 1.517 and 1.621 respectively . It is desired to form an achromatic combination of prisms of crown and flint glasses which can produce a deviation of 1° in the yellow ray. The refracting angle of the flint glass prism is

Question 28 :
On a hot summer night, the refractive index of air is smallest near the ground and increases with height from the ground. When a light beam is directed horizontally, the Huygens' principle leads us to conclude that as it travels, the light beam:

Question 29 :
A Young's double slit experiment is conducted in water {tex} \left( \mu _ { 1 } \right) {/tex} as shown in figure. A glass plate of thickness t and refractive index {tex} \mu _ { 2 } {/tex} is placed in the path of {tex} S _ { 2 } {/tex} . The optical path difference at {tex} O {/tex} is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f101e5db655bbf10a76e"><br>

Question 30 :
Two coherent point sources {tex} \mathrm { S } _ { 1 } {/tex} and {tex} \mathrm { S } _ { 2 } {/tex} are separated by a small distance d as shown. The fringes obtained on the vertical screen will be:<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f14bd3eb695bc07eb5f8"><br>

Question 31 :
Two light waves superimposing at the mid-point of the screen are coming from coherent sources of light with phase difference {tex} 3\pi {/tex} rad. Their amplitudes are {tex} 1\mathrm { cm } {/tex} each. The resultant amplitude at the given point will be.

Question 32 :
The angle between the incident ray and the normal is called ________.<br>

Question 33 :
Which type of an image is formed by a plane mirror?

Question 34 :
A point source of light B is placed at a distance L in front of the centre of a mirror of width 'd' hung vertically on a wall. A man walks in front of the mirror along a line parallel to the mirror at a distance 2L from it as shown in fig. The greatest distance over which he can see the image of the light source in the mirror is:<br /><img style='object-fit:contain' src="https://s3.ap-south-1.amazonaws.com/me-p/5f630e9b16d7e6154e4565d8.jpg" />

Question 35 :
A cubical room is formed with $6$ plane mirror. An insect moves along diagonal of the floor with uniform speed. The velocity of its image in two adjacent walls are $20\sqrt 2 $ cm/s. Then the velocity of image formed by the roof is ;

Question 36 :
A ray is incident at an angle $38^o $ on a mirror. The angle between normal and reflected ray is _________.

Question 37 :
Figure shows behavior of a wavefront when it passes through a prism.<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5d60f070e5db655bbf10a656"><br>Which of the following statements is/are correct?

Question 38 :
The glancing angle of incidence is $10^{\circ}$. What will be the glancing angle of reflection?

Question 39 :
A point source of 100 candela is held 5m above a sheet of blotting paper which reflects 75% of light incident upon it. The illuminance of blotting paper is

Question 40 :
If yellow light emitted by sodium lamp in Young's double slit experiment is replaced by a monochromatic blue light of the same intensity

Question 41 :
When unpolarised light is incident on a plane glass plate at Brewster's angle, then which of the following statements is correct?

Question 42 :
The refractive index of water is 1.33. The direction in which a man under water should look to see the setting sun is [MP PET 1991; Kerala PET 2002; Pb. PET 2003]

Question 43 :
The condition for obtaining secondary maxima in the diffraction pattern due to single slit is

Question 44 :
In which one of the following regions of the electromagnetic spectrum will the vibrational motion of molecules give rise to absorption

Question 45 :
If two waves represented by {tex} \mathrm { y } _ { 1 } = 4 \sin \omega t {/tex} and {tex} \mathrm { y } _ { 2 } =3\sin \left( \omega \mathrm { t } + \frac { \pi } { 3 } \right) {/tex} interfere at a point, then the amplitude of the resulting wave will be about