Rotational Dynamics — Physics STD 12 Science — Question

In Young's double-slit experiment using monochromatic light, the fringe pattern shifts by certain distance on the screen when a mica sheet of refractive index 1.6 and thickness 1.964 microns is introduced in the path of one of the interfering waves. The mica sheet is then removed and the slits-to-screen distance is doubled. It is found that the distance between successive maxima now is the same as the observed fringe shift with the mica sheet. Calculate the wavelength of the monochromatic light used.

With the help of neat diagrams, explain how a nonpolar dielectric material is polarised in an external electric field.
OR
Explain the behaviour of nonpolar dielectric material in an external electric field.

Explain the construction and propagation of a plane wavefront using Huygens’ principle.

Derive an equation for the resultant wave produced due to superposition of two waves. Hence, state the expression for the amplitude of the resultant wave when two waves are
(1) in phase
(2) out of phase.

With the help of a neat diagram, explain the working of the npn transistor?

Draw a neat diagram of a full wave rectifier and explain it’s working.

Define and explain velocity gradient in a steady flow.