1
JEE Main 2021 (Online) 31st August Evening Shift
Numerical
+4
-1
In a Young's double slit experiment, the slits are separated by 0.3 mm and the screen is 1.5 m away from the plane of slits. Distance between fourth bright fringes on both sides of central bright is 2.4 cm. The frequency of light used is ______________ $$\times$$ 1014 Hz.
2
JEE Main 2021 (Online) 26th August Evening Shift
Numerical
+4
-1
A source of light is placed in front of a screen. Intensity of light on the screen is I. Two Polaroids P1 and P2 are so placed in between the source of light and screen that the intensity of light on screen is I/2. P2 should be rotated by an angle of (degrees) so that the intensity of light on the screen becomes $${{3I} \over 8}$$.
3
JEE Main 2021 (Online) 26th August Morning Shift
Numerical
+4
-1
White light is passed through a double slit and interference is observed on a screen 1.5 m away. The separation between the slits is 0.3 mm. The first violet and red fringes are formed 2.0 mm and 3.5 mm away from the central white fringes. the difference in wavelengths of red and violet light is ................ nm.
4
JEE Main 2021 (Online) 27th July Evening Shift
Numerical
+4
-1
The difference in the number of waves when yellow light propagates through air and vacuum columns of the same thickness is one. The thickness of the air column is ___________ mm. [Refractive index of air = 1.0003, wavelength of yellow light in vacuum = 6000 $$\mathop A\limits^o$$]