Types Of Semiconductors

Which one of the following statements is false?

1.	Pure Si doped with trivalent impurities gives a p-type semiconductor.
2.	The majority of carriers in an n-type semiconductor are holes.
3.	The minority carriers in a p-type semiconductor are electrons.
4.	The resistance of intrinsic semiconductors decreases with an increase in temperature.

In an type semiconductor, which of the following statement is true?

1.	Electrons are minority carriers and pentavalent atoms are dopants.
2.	Holes are minority carriers and pentavalent atoms are dopants.
3.	Holes are the majority carriers and trivalent atoms are dopants.
4.	Electrons are the majority carriers and trivalent atoms are dopants.

For a type semiconductor, which of the following statements is true?

1.	Electrons are the majority carriers and pentavalent atoms are the dopants.
2.	Electrons are the majority carriers and trivalent atoms are the dopants.
3.	Holes are the majority carriers and trivalent atoms are the dopants.
4.	Holes are the majority carriers and pentavalent atoms are the dopants.

An intrinsic semiconductor is converted into an type extrinsic semiconductor by doping it with:
1. phosphorous
2. aluminium
3. silver
4. germanium

The electron concentration in an type semiconductor is the same as the hole concentration in a type semiconductor. An external field (electric) is applied across each of them. Compare the currents in them.

1.	current in type current in type.
2.	no current will flow in type, current will only flow in type.
3.	current in type current in type.
4.	current in type current in type.