If a die is thrown at random, then the expectation of the number on it is

A body slides down a smooth inclined plane having angle $$\theta$$ and reaches the bottom with velocity $$v$$. If a body is a sphere, then its linear velocity at the bottom of the plane is

A light wave of wavelength $$\lambda$$ is incident on a slit of width $$d$$. The resulting diffraction pattern is observed on a screen at a distance $$D$$. If linear width of the principal maxima is equal to the width of the slit, then the distance $$D$$ is

The damping force of an oscillator is directly proportional to the velocity. The unit of constant of proportionality is