zigya tab
In an unbiased p-n junction, holes diffuse from the p-region to n-region because
(a)    free electrons in the n-region attract them.
(b)    they move across the junction by the potential difference.
(c)    hole concentration in p-region is more as compared to n-region.
(d)    all the above.

(c) is the correct statement. 

In an unbiased p-n junction, hole concentration in p-region is more than in n-region and due to difference in concentration of charge carriers, holes diffuse from p-region to n-region.
1977 Views

State True or False:

When a forward bias is applied to a p-n junction, it

A.

Raises the potential barrier.

B.

Reduces the majority carrier current to zero.

C.

Lowers the potential barrier.

D.

None of the above.

A. FALSE
B. FALSE
C. TRUE
D. FALSE
When a forward bias is applied across the p-n junction, the applied voltage opposes the barrier voltage. Due to it, the potential barrier across the junction is lowered. Hence answer (c) is correct.
1050 Views

Which of the statements given in Question 14.1 is true for p-type semiconductors.

In p-type semiconductor holes are majority carriers and electrons are minority carriers and p-type semiconductor is obtained by doping Ge or Si with trivalent atoms.  

Hence (d) is correct.
823 Views

Advertisement

In an n-type silicon, which of the following statement is true:
(a)    Electrons are majority carriers and trivalent atoms are the dopants.
(b)    Electrons are minority carriers and pentavalent atoms are the dopants.
(c)    Holes are minority carriers and pentavalent atoms are the dopants.
(d)    Holes are majority carriers and trivalent atoms are the dopants.


N-type semiconductor is obtained by doping the Ge or Si with pentavalent atoms and also, electrons are majority carriers and holes are minority carriers.

Hence answer (c) is true.
1655 Views

Advertisement
Carbon, silicon and germanium have four valence electrons each. These are characterised by valence and conduction bands separated by energy band gap respectively equal to (Eg)C, (Eg)Si and (Eg)Ge. Which of the following statements is true?
(a)    (Eg)Si < (Eg)Ge < (Eg)C
(b)    (Eg)C < (Eg)Ge > (Eg)Si
(c)    (Eg)C > (Eg)Si > (Eg)Ge
(d)  (Eg)C = (Eg)Si = (Eg)Ge

(c) is the correct statement. 

Out of the given three elements, energy band gap is maximum for carbon, less for silicon and least for germanium.  

1125 Views

Advertisement