JIPMER 2012
- Exam
- JIPMER
- Year
- 2012
- Subject
- Physics
- Chapter
- Ray Optics
JIPMER 2012 · Physics · Ray Optics
The two lenses of an achromatic doublet should have
The two lenses of an achromatic doublet should have
Options
- Aequal powers
- Bequal dispersive powers
- Cequal ratio of their power and dispersive power
- Dsum of the product of their powers and dispersive power equal to zero
Correct answer
D. sum of the product of their powers and dispersive power equal to zero
Step-by-step solution
An achromatic doublet is a pair of two lenses such that the combination does not split light into its constituent colors.
Therefore, the net dispersive power of the system must be zero. The mathematical condition then becomes that sum of product of their powers and dispersive powers equal to zero.