A closed organ pipe of length L and an open organ pipe contain gases of densities $$\rho$$₁ and $$\rho$$₂ respectively. The compressibility of gases are equal in both the pipes. Both the pipes are vibrating in their first overtone with same frequency. The length of the open pipe is $${x \over 3}L\sqrt {{{{\rho _1}} \over {{\rho _2}}}} $$ where x is ___________. (Round off to the Nearest Integer)

A swimmer can swim with velocity of 12 km/h in still water. Water flowing in a river has velocity 6 km/h. The direction with respect to the direction of flow of river water he should swim in order to reach the point on the other bank just opposite to his starting point is ____________$$^\circ$$. (Round off to the Nearest Integer) (Find the angle in degrees)

A deviation of 2$$^\circ$$ is produced in the yellow ray when prism of crown and flint glass are achromatically combined. Taking dispersive powers of crown and flint glass as 0.02 and 0.03 respectively and refractive index for yellow light for these glasses are 1.5 and 1.6 respectively. The refracting angles for crown glass prism will be ____________$$^\circ$$ (in degree). (Round off to the Nearest Integer)

A force $$\overrightarrow F $$ = $${4\widehat i + 3\widehat j + 4\widehat k}$$ is applied on an intersection point of x = 2 plane and x-axis. The magnitude of torque of this force about a point (2, 3, 4) is ___________. (Round off to the Nearest Integer)