Bi-quartz Polarimeter

Q.What is Polarimeter?

A.It is a device used to measure the angle of rotation of plane of polarisation rotated by an optically active substance.

Q.What is specific rotation?

A.Specific rotation of an optically active substance at a given temperature is the rotation in degrees of the plane of polarisation of incident polarized beam produced by one decimeter length of substance of unit concentration.

Q.What are optically active substances?

A.Optically active substances rotate the plane of polarisation or plane of vibration of plane polarised light when it passes through it.

Q.What are different optically active substances?

A.Right handed or dextro rotatory & left handed or leavo rotatory 

Q.Define plane of polarisation

A.It is the plane passing through the direction of propagation of light.

Q.Define plane polarised light.

A.Light is said to be plane polarised if it has vibrations in a single direction perpendicular to direction of propagation. 

Q.Define plane of vibration.

A.It is the plane containing the direction of vibration and direction of propagation.

Q.How does specific rotation depend on temperature?

A.In some substances it decreases with rise in temperature like turpentine while in quartz it increases.

Q.What is the unit of specific rotation?

A.degree/decimeter/gm/cc

Q.name one practical use of polarimeter.

A.It is used to measure percentage of sugar in a solution.

Q.What is the function of analyzer and polariser?

A. Polariser changer ordinary light to plane polarised light and analyzer is used to analyse light emitted through the optically active substance.

Q.What is Bi-quartz device?

A.It consists of two semicircular disc of right handed and left handed quartz which are cemented together to form a circular disc.

Bi-quartz polarimeter