Semiconductors

An atom consists of

• one nucleus and only one electron

• one nucleus and one or more electrons

• protons, electrons and neutrons

• answer (b) and (c)

The nucleus of an atom is made up of

• protons and neutrons

• electrons

• electrons and protons

• electrons and neutrons

Tags

NGSS.HS-PS1-8

The most widely used semi-conductive material in electronic device

• germanium

• carbon

• cooper

• silicon

The energy band in which free electrons exist is the

• first band

• second band

• conductive band

• valence band

1. The resistivity of a semiconductor lies between 

• (a)10 ^-6 Ωm to10^-8 Ωm
• n(b) 10⁸ Ωm to10¹⁴ Ωm
• (c) 10 ^-2 Ωm to10⁴ Ωm
• (d) none of these

2. The forbiddenn energy gap for Germanium is of the order of

• (a) 0.7 eV
• (b) 0.3 eV
• (c) 1.1 eV
• (d) 10 eV

3. Which of the following is a pentavalent impuity added while forming an extrinsic semiconductor ?

• (a) Boron 
• Arsenic
• Indium
• Gallium

The reverse saturation current in a PN Junction diode is only due to 

• majority carriers
• minority carriers
• acceptor ions
• donor ions

Doping of Semiconductors

• materials which can conduct electricity better than insulator, but not as well as conductors.

• The process of adding of a certain amount of specific impurities atoms in the pure semiconductor.

• when 4 electrons in outermost orbit.

Tags

NGSS.HS-PS1-3

which statement is correct? (the dark circles represent the electrons)

• p-type of the diode is connected to the negative terminal.

• Electron moves across the p-n junction, makes the diode forward biased

• current will not flow in the circuit

• reverse biased circuit

Tags

NGSS.HS-PS3-5