Question 1 :
Figure here shows {tex} P {/tex} and {tex} Q {/tex} as two equally intense coherent sources emitting radiations of wavelength {tex} 20 \mathrm { m } {/tex}. The separation {tex} P Q {/tex} is {tex} 5.0 \mathrm { m } {/tex} and phase of {tex} P {/tex} is ahead of the phase of {tex} Q {/tex} by {tex} 90 . A , B {/tex} and {tex} C {/tex} are three distant points of observation equidistant from the mid-point of {tex} P Q . {/tex} The intensity of radiations at {tex} A , B , C {/tex} will bear the ratio<br> <img style='object-fit:contain' src='https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5dc53af94548337453d21600' />

Question 2 :
A star emitting light of wavelength {tex} 5896 \mathrm { A } ^{\circ}{/tex} is moving away from the earth with a speed of {tex} 3600 \mathrm { km } / \mathrm { sec } . {/tex} The wavelength of light observed on earth will<br>{tex} \left( c = 3 \times 10 ^ { 8 } \mathrm { m } / \mathrm { sec } \text { is the speed of light } \right) {/tex}<br>

Question 3 :
Two coherent sources have intensity in the ratio of {tex} \frac { 100 } { 1 } {/tex} . Ratio of (intensity) max/(intensity) min is

Question 4 :
{tex}\mathbf {Assertion}{/tex}: Radio waves can be polarised.<br> {tex}\mathbf {Reason}{/tex} : Sound waves in air are longitudinal in nature

Question 5 :
In a converging lens of focal length {tex} f {/tex} and the distance between real object and its real image is {tex} 4 f . {/tex} If the object moves {tex} x _ { 1 } {/tex} distance towards lens, its image moves {tex} x _ { 2 } {/tex} distance away from the lens and when object moves {tex} y _ { 1 } {/tex} distance away from the lens its image moves {tex} y _ { 2 } {/tex} distance towards the lens, then choose the correct option<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5d5bb2d85637834a58898764"><br>

Question 6 :
A car is fitted with a convex side-view mirror of focal length {tex} 20 \mathrm { cm } . {/tex} A second car {tex}2.8 \mathrm { m } {/tex} behind the first car is overtaking the first car at a relative speed of {tex}15\, \mathrm { m } / \mathrm { s } {/tex} . The speed of the image of the second car as seen in the mirror of the first one is:

Question 7 :
A point object is moving along the principle axis of a concave mirror at rest of focal length 30cm with speed 5m/s towards the mirror. Find the speed of image of object when object is at a distance 60cm from mirror. <br> <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c851bfef6349df01003d"/>

Question 8 :
{tex}\mathbf {Assertion}{/tex} : The electrical conductivity of earth's atmosphere decrease with altitude.<br>{tex}\mathbf {Reason}{/tex} : The high energy particles (i.e. {tex} \gamma {/tex} -rays and cosmic rays) coming from outer space and entering our earth's atmosphere causes ionisation of the atoms of the gases present there and the pressure of gases decreases with increase in altitude.<br>

Question 10 :
For a concave mirror of focal length 20 cm, if the object is at a distance of 30 cm from the pole, then the nature of the image and its magnification will be

Question 11 :
An initially parallel cylindrical beam travels in a medium of refractive index {tex} \mu ( I ) = \mu _ { 0 } + \mu _ { 2 } I , {/tex} where {tex} \mu _ { 0 } {/tex} and {tex} \mu _ { 2 } {/tex} are positive constants and I is the intensity of the light beam. The intensity of the beam is decreasing with increasing radius.<br>As the beam enters the medium, it will<br>

Question 12 :
In a displacement method using convex lens, two images are obtained for a separation of {tex} d {/tex} between the positions of the lens. One image is magnified and the other is diminished. If {tex} m {/tex} is the magnification of one image, the focal length of the lens is {tex}( m > 1 ) {/tex}

Question 13 :
A light ray falls on a square slab at an angle {tex} 45 ^ { \circ } . {/tex} What must be the minimum index of refraction of glass, if total internal reflection takes place at the vertical face?<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5d5bb2485637834a588986e3"><br>

Question 14 :
A prism (<font face="Symbol">&micro;</font> = 1.5) has a refracting angle of 30<font face="Symbol">&deg;</font>. The deviation of a monochromatic ray incident normally on its one surface will be (sin48<font face="Symbol">&deg;</font>36′ = 0.75)

Question 15 :
A ray of light enters into a transparent liquid from air as shown in the figure. The refractive index of the liquid varies with depth <em>x</em> from the topmost surface as {tex}\mu = \sqrt{2} - \frac{1}{\sqrt{2}}{/tex}<em>x</em> where <em>x</em> in meters. The depth of the liquid medium is sufficiently large. The maximum depth reached by the ray inside the liquid is <img style='object-fit:contain' style="max-width:240px;" src="https://storage.googleapis.com/teachmint/question_assets/JEE%20Main/5f16c83dbfef6349df010029"/>