Show that, two thin lenses kept in contact, form an achromatic doublet if they satisfy the condition.
`(omega)/(f)+(omega.)/(f.)=0`
where the terms have their usual meaning.

Starting with the law of radioactive disintegration, show that : N=N_(0)e^(-lamdat) , where the terms have their usual meaning.

Derive R = 2f for a spherical mirror, where the symbols have their usual meaning

What condition must be satisfied by two thin lenses kept in contact so that they form an achromatic doublet, i.e., a combination free from chromatic aberration ?

For two thin lenses kept in contact with each other, show that : " "1/F=1/f_(1)+1/f_(2) where the terms have their usual meaning.

A : When two lenses in contact form an achromatic doublet, then the materials of the two lenses are always different. R : The dispersive powers of the materials of the two lenses are of opposite sign.

For radioactive disintegration of a radioactive substance, show that N = N_(0)e^(-lambdat) where the terms have their usual meaning,

With the help of a labelled diagram, show that the balancing condition of a Wheatstone bridge is : (R_(1))/(R_(2))=(R_(3))/(R_(4)) where the terms have their usual meaning.