Non existence of free electrons in the nucleus

At room temperature, an intrinsic semiconductor has ……….

• Many holes only

• A few free electrons and holes

• Many free electrons only

• No holes or free electrons

A Balmer series spectrum is formed when electrons from excited state fall down to ground state of n= ___.

Electrons and holes are equal in magnitude but opposite in polarity

• True

• False

Free electron theory has been developed in ----------- main stages

• 1

• 2

• 3

• 5

This is a graph that is seen on CRO. How is it change after full wave rectification process?

• 
• 
• 
• 

Highest energy level that can be occupied by an electron at 0 K

• Excited state

• Conduction state

• Fermi energy

• Average energy

In QFET, Energy levels are

• discrete

• continuous

• discontinuous

• has increasing value

Wolfgang Pauli formulated the law stating that ____ electrons can have the same set of quantum numbers.

• no two

• only two

• only one

• no one

Q4. Identify the device:

• Bainbridge and Jordan Double Focusing Mass spectrograph

• Bainbridge Mass spectrograph

• Mass Spectrograph

• None of the above

Who's model does this picture represent?

• Dalton: 1803-1808

• Thomson 1897

• Rutherford 1911

• Bohr 1913