A plane polarized light is incident on a polariser with its pass axis aking angle $$\theta $$ with x-axis, as shown in the figure. At four different values of $$\theta ,\,\theta $$ = 8^o, 38^o, 188^o and 218^o, the observed intensities are same.
What is the angle between the direction of polarization and x-axis ?

A disc rotates about its axis of symmetry in a horizontal plane at a steady rate of $$3.5$$ revolutions per second. A coin placed at a distnce of 1.25 cm from the axis of rotation remains at rest on the disc. The coefficient of friction between the coin and the disc is : (g = 10 m/s²)

A thin uniform bar of length $$L$$ and mass $$8$$ m lies on a smooth horizontal table. Two point masses m and 2 m are moving in the same horizontal plane from opposite sides of the bar with speeds 2$$\upsilon $$ and $$\upsilon $$ respectively. The masses stick to the bar after collision at a distance $${L \over 3}$$ and $${L \over 6}$$ respectively from the center of the bar. If the br starts rotating about its center of mass as a result of collision, the angular speed of the bar will be :

A body of mass 2 kg slides down with an acceleration of 3 m/s² on a rough inclined plane having a slope of $${30^o}$$. The external force required to take the same body up the plane with the same acceleration will be : (g = 10 m/s²)