Wave Optics — Physics STD 12 Science — Question

Write expression for speed of electro-magnetic waves in a medium.

A source emits 45 joules of energy in 15s. What is the radiant flux of the source?

Two converging lenses of unequal focal lengths can be used to reduce the aperture of a parallel beam of light without losing the energy of the light. This increases the intensity. Describe how the converging lenses should be placed to do this.

What will be the shape of the wave front emitted by a light source in the form of a narrow slit?

Can the potential energy in a simple harmonic motion be negative? Will it be so if we choose zero potential energy at some point other than the mean position?

Define the term 'stopping potential' in relation to photoelectric effect.

If it were possible for a gas in a container to reach the temperature 0K, its pressure would be zero. Would the molecules not collide with the walls? Would they not transfer momentum to the walls?

Two Polaroids are placed with their optic axis perpendicular to each other. One of them is rotated through 45°, what is the intensity of light emerging from the second Polaroid if I₀ is the intensity of unpolarised light?

Consider the situation described in the previous problem. Suppose the current i enters the loop at the point A and leaves it at the point B. Find the magnetic field at the centre of the loop.