1
JEE Main 2016 (Online) 9th April Morning Slot
+4
-1
In Young’s double slit experiment, the distance between slits and the screen is 1.0 m and monochromatic light of 600 nm is being used. A person standing near the slits is looking at the fringe pattern. When the separation between the slits is varied, the interference pattern disappears for a particular distance d0 between the slits. If the angular resolution of the eye is $$({{{1}} \over {60}})^o$$, the value of d0 is close to :
A
1 mm
B
2 mm
C
4 mm
D
3 mm
2
JEE Main 2016 (Offline)
+4
-1
The box of a pin hole camera, of length $$L,$$ has a hole of radius a. It is assumed that when the hole is illuminated by a parallel beam of light of wavelength $$\lambda$$ the spread of the spot (obtained on the opposite wall of the camera) is the sum of its geometrical spread and the spread due to diffraction. The spot would then have its minimum size (say $${b_{\min }}$$) when :
A
$$a = \sqrt {\lambda L} \,$$ and $${b_{\min }} = \sqrt {4\lambda L}$$
B
$$a = {{{\lambda ^2}} \over L}$$ and $${b_{\min }} = \sqrt {4\lambda L}$$
C
$$a = {{{\lambda ^2}} \over L}$$ and $${b_{\min }} = \left( {{{2{\lambda ^2}} \over L}} \right)$$
D
$$a = \sqrt {\lambda L}$$ and $${b_{\min }} = \left( {{{2{\lambda ^2}} \over L}} \right)$$
3
JEE Main 2015 (Offline)
+4
-1
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 :
A
bends down wards
B
bends upwards
C
becomes narrower
D
goes horizontally without any deflection
4
JEE Main 2015 (Offline)
+4
-1
Assuming human pupil to have a radius of $$0.25$$ $$cm$$ and a comfortable viewing distance of $$25$$ $$cm$$, the minimum separation between two objects that human eye can resolve at $$500$$ $$nm$$ wavelength is :
A
$$100\,\mu m$$
B
$$300\,\mu m$$
C
$$1\,\mu m$$
D
$$30\,\mu m$$
EXAM MAP
Medical
NEET