1
JEE Main 2019 (Online) 11th January Morning Slot
+4
-1
In a Young's double slit experiment, the path difference, at a certain point on the screen, between two interfering waves is $${1 \over 8}$$ th of wavelength. The ratio of the intensity at this point to that at the centre of a bright fringe is close to :
A
0.94
B
0.85
C
0.74
D
0.80
2
JEE Main 2019 (Online) 11th January Morning Slot
+4
-1
An object is at a distance of 20 m from a convex lens of focal length 0.3 m. The lens forms an image of the object. If the object moves away from the lens at a speed of 5 m/s, the speed and direction of the image will be :
A
1.16 $$\times$$ 10–3 m/s towards the lens
B
2.26 $$\times$$ 10–3 m/s away from the lens
C
3.22 × 10–3 m/s towards the lens
D
0.92 $$\times$$ 10$$-$$3 m/s away from the lens
3
JEE Main 2019 (Online) 11th January Morning Slot
+4
-1
The variation of refractive index of a crown glass thin prism with wavelength of the incident light is shown. Which of the following graphs is the correct one, if Dm is the angle of minimum deviation?

A
B
C
D
4
JEE Main 2019 (Online) 10th January Evening Slot
+4
-1
The eye can be regarded as a single refracting surface. The radius of curvature of this surface is equal to that of cornea (7.8 mm). This surface separateds two media of refractive indices 1 and 1.34. Calculate the distance from the refracting surface at which a parallel beam of light will come to focus -
A
2 cm
B
3.1 cm
C
4.0 cm
D
1 cm
JEE Main Subjects
Physics
Mechanics
Electricity
Optics
Modern Physics
Chemistry
Physical Chemistry
Inorganic Chemistry
Organic Chemistry
Mathematics
Algebra
Trigonometry
Coordinate Geometry
Calculus
EXAM MAP
Joint Entrance Examination