Untitled Lesson

Multiple Choice

Which of the following is created when pentavalent impurities are added to a semiconductor?

• Free electrons

• Holes

• Bound electrons

• 1. Valence electrons

Fill in the Blanks

How many valence electrons do trivalent impurities have?

Multiple Choice

What is the resistivity of a semiconductor?

• More than that of insulators and conductors

• Between that of insulators and conductors

• Less than that of insulators and conductors

• None of the above

Multiple Choice

Which among the following is the most widely used semiconductor material?

• Potassium

• Phosphorous

• Silicon

• Arsenic

Multiple Choice

The energy gap between the valence band and the conduction band in a semiconductor is

• 5 eV

• 10 eV

• 15 eV

• 1 eV

Multiple Choice

How many valence electrons are there in semiconductors?

• 2

• 3

• 4

• 7

Multiple Choice

When a pentavalent impurity is introduced into a pure semiconductor, it transforms into

• Intrinsic

• n-type

• p-type

• None of the above

Multiple Choice

What is the other name for a pentavalent impurity?

• Donor impurity

• Acceptor impurity

• Ionic impurity

• None of the above

Multiple Choice

What will happen when a hole and electron are in close proximity?

• Repel each other

• Have no effect on each other

• Attract each other

• None of the above

Multiple Choice

What is the charge on a n-type semiconductor

• Positively charged

• Electrically neutral

• Negatively charged

• None of the above

Multiple Choice

The electrical resistance of the depletion layer is large because

• It has no change carriers

• It has a large number of charge carriers

• It contains electrons as charge carriers

• It has holes as charge carriers

Multiple Choice

The PN junction diode is used as

• An amplifier

• A rectifier

• An oscillator

• 1. A modulator

Multiple Choice

When a PN junction diode is reverse biased

• Electrons and holes are attracted towards each other and move towards the depletion region

• Electrons and holes move away from the junction depletion region

• Height of the potential barrier decreases

• No change in the current takes place