When we excite some atoms by heat collision or electrical discharge they will________________?

Related Mcqs:

1. Motorcycle safety helmet extends the time of collision hence decreasing the________________?

   A. chance of collision
   B. force acting
   C. velocity
   D. impulse

2. The collision between two bodies be elastic if bodies are_________________?

   A. solid and soft
   B. soft and elastic
   C. solid and hard
   D. hard and elastic

3. When collision between the bodies in a system is inelastic in nature then for system ____________________?

   A. momentum changes but K.E remain conserve
   B. K.E changes but momentum remain conserve
   C. both momentum and K.E changes
   D. both momentum and K.E remain conserve

4. Electrical energy is converted to heat at the rate of___________________?

   A. IRt
   B. I2R
   C. I2Rt
   D. VIt

5. Excited atoms return to their ground state in_______________?

   A. 10-10s
   B. 10-8s
   C. 10-6s
   D. 10-9s

6. In laser production the state in which more atoms are in the upper state than in the lower one is called_____________?

   A. Metal stable state
   B. Normal state
   C. Inverted population
   D. All the above

7. Materials in which valence electrons are tightly bound to their atoms at low temperature are called___________________?

   A. Semi conductor
   B. Super conductors
   C. Insulators
   D. Conductor

8. If the density of atoms remain same along any direction in a crystal is called__________________?

   A. Symmetry
   B. Homogeneity
   C. Isotropy
   D. Cleavage

9. Semi-conductors with donor atoms and free electrons belong to the type________________?

   A. n
   B. p
   C. mix
   D. any of above

10. To obtain a p-type semi-conductor Si Crystal must be doped with foreign atoms whose valency is_____________?

    A. 2
    B. 3
    C. 4
    D. 5