Tag: solid state

Quizzes (4) Questions (214)

Questions Related to solid state

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

The electrical resistivity of a semiconductor:

  1. increases with temperature

  2. decreases with temperature

  3. increases at low temperature and then decreases

  4. does not change with temperature
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As the temperature increase the electrons in the valence band get excited and jump into the conduction band and hence the conductance increases and conductance is inversely proportional to resistivity. Hence, resistivity decreases.

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

Which of the following, when doped into ultrapure germanium, will convert it into a p-type semiconductor?

  1. $C$
  2. $As$
  3. $In$
  4. $Na$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

When a pure semiconductor is doped with trivalent elemental impurity $p$ type semiconductors are formed

(A) $C\longrightarrow Tetravalent$
(B) $As\longrightarrow Pentavalent$
(C) $Indium$ $(In)\longrightarrow$ $Trivalent$
(D) $Na\longrightarrow$ $Monovalent$
Thus Indium ($In$) will convert ultrapure germanium into p-type semiconductor.

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

Superconductivity may be defined as a phenomenon in which metals, alloys and chemical compounds become perfect conductors with zero resistivity at temperatures approaching __________.

  1. room temperature

  2. zero temperature

  3. absolute zero

  4. all of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Superconductivity may be defined as a phenomenon in which metals, alloys and chemical compounds become perfect conductors with zero resistivity at temperatures approaching absolute zero.

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

Which of the following represent(s) true statement(s)?

  1. The electrical resistance of metal does not depends upon temperature.

  2. Electrical resistance increases with decrease in temperature.

  3. The electrical resistance becomes almost zero near the absolute temperature.

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The following represents true statements. The electrical resistance of metal depends upon temperature. Electrical resistance decreases with decrease in temperature. The electrical resistance becomes almost zero near the absolute temperature.

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

The temperature at which a substance starts behaving as super-conductor is called _________.

  1. normal temperature

  2. transition temperature

  3. regular temperature

  4. all of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The temperature at which a substance starts behaving as super-conductor is called transition temperature. For most metals, the transition temperature lies between 2 and 5 K.

Multiple choice chemistry solid state electrical and magnetic properties of solids impurity defects properties of solids

In a n-type semiconductor, which of the following statements is true?

  1. Electrons are majority carriers and trivalent atoms are dopants.

  2. Electrons are minority carriers and pentavalent atoms are dopants.

  3. Holes are minority carriers and pentavalent atoms are dopants.

  4. Holes are majority carriers and trivalent atoms are dopants.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The n-type semiconductor can be produced  by doping impurity atoms of valence 5 i.e, pentavalent atoms like phosphorous and so electrons are majority charge carriers and Holes are minority charge carriers.

So correct answer is option C.