question_answer

Certain substance emits only the wavelengths \[{{\lambda }_{1}},\ {{\lambda }_{2}},\ {{\lambda }_{3}}\] and \[{{\lambda }_{4}}\] when it is at a high temperature. When this substance is at a colder temperature, it will absorb only the following wavelengths                                                                 [MP PET 1990]

A)            \[{{\lambda }_{1}}\]          

B)            \[{{\lambda }_{2}}\]

C)            \[{{\lambda }_{1}}\] and \[{{\lambda }_{2}}\]           

D)            \[{{\lambda }_{1}},\ {{\lambda }_{2}},\ {{\lambda }_{3}}\] and \[{{\lambda }_{4}}\]