Join PAF MCQS Test Past Papers Physics download pdf online practice tests
1.Diamond is an electrical.
A. Conductor
B. Semiconductor
C. Superconductor
D. Insulator
ANSWER: D
2.Both electrons and holes serve as charge carriers when the silicon is put under a.
A. Pressure
B. Temperature
C. Conductor
D. Potential difference
ANSWER: D
3.A semiconductor is formed by which bond.
A. Covalent
B. Electrovalent
C. Co-ordinate
D. None
ANSWER: A
4.The most commonly used semiconductor is.
A. Germanium
B. Silicon
C. Carbon
D. Sulphur
ANSWER: B
5.A semiconductor has generally how many valence electrons.
A. 2
B. 3
C. 6
D. 4
ANSWER: D
6.When a pure semiconductor is heated, its resistance.
A. Goes up
B. Goes down
C. Remains the same
D. None
ANSWER: B
7.When a pentavalent impurity is added to a pure semiconductor, it becomes.
A. An insulator
B. An intrinsic semiconductor
C. P-type semiconductor
D. N-type semiconductor
ANSWER: D
8.Addition of pentavalent impurity to a semiconductor creates many.
A. Free electrons
B. Holes
C. Valence electrons
D. Bound electrons
ANSWER: A
9.The number of valence electrons in pentavalent impurity is.
A. 3
B. 5
C. 4
D. 6
ANSWER: B
10.An n-type semiconductor is.
A. Positively charged
B. Negatively charged
C. Electrically neutral
D. None of the above
ANSWER: C
11.A trivalent impurity has how many valence electrons.
A. 4
B. 5
C. 6
D. 3
ANSWER: D
12.Addition of trivalent impurity to a semiconductor creates many.
A. Holes
B. Free electrons
C. Valence electrons
D. Bound electrons
ANSWER: A
13.As the doping to a pure semiconductor increases, the bulk resistance of the semiconductor.
A. Remains the same
B. Increases
C. Decreases
D. None of the above
ANSWER: C
14.In a semiconductor, current conduction is due to.
A. Only holes
B. Only free electrons
C. Holes and free electrons
D. None of the above
ANSWER: C
15.In the depletion region of a pn junction, there is a shortage of.
A. Acceptor ions
B. Holes and electrons
C. Donor ions
D. None of the above
ANSWER: B