MPSC PYQ

Metastable state

Tested in 2 real MPSC questions across 1 year (20142014). See it in context on the interactive Concept Graph →

Years it was asked

What you need to know first

Laser transitionsEnergy levels

Real questions that test this

चतुःस्तरीय लेझर दरम्यानच्या प्रक्रियेमध्ये, अंशस्थिर स्थितीचे परिवहन ______ संपुष्टात येते. / During lasing action of a four level laser transition from metastable state ends at :

a)उच्चतम उत्तेजीत स्थितीत / Higher excited state
b)निम्नतम स्थिती / ground state
c)अंशस्थिर आणि निम्नतम स्थितीच्या मध्ये / Intermediate state between metastable and ground state✓ Correct
d)यापैकी एकही नाही / None of the above

In a four-level laser, the transition from the metastable state during lasing action ends at an intermediate state located just above the ground state.

प्रेरित उत्सर्जन प्रक्रियेसाठी त्रिस्तरीय लेझर मध्ये ______ . / For induced emission in a three level laser :

a)50% अणू अंशस्थिर स्थितीत असतात. / 50% of atoms should be in metastable state.
b)50% पेक्षा कमी अणू अंशस्थिर स्थितीत असतात. / < (less than) 50% of atoms should be in metastable state
c)50% पेक्षा जास्त अणू अंशस्थिर स्थितीत असतात. / > (more than) 50% of atoms should be in metastable state&check; Correct
d)अंशस्थिर स्थिती रिक्त असते. / metastable state must be vacant

In a three-level laser system, population inversion requires more than 50% of the atoms to be pumped into the metastable state so that stimulated emission can dominate over absorption.