## Class 12 Physics MCQs Semiconductor Electronics: Materials, Devices And Simple Circuits for JEE/NEET

Here, you will get Class 12 Physics MCQ of Chapter 14 Semiconductor Electronics: Materials, Devices And Simple Circuits for cracking JEE and NEET/AIIMS. By solving these MCQs of Class 12 Physics Chapter 14 Semiconductor Electronics: Materials, Devices And Simple Circuits, you will get the confidence to crack JEE or NEET. Practice MCQ Questions for Class 12 Physics with Answers on a daily basis and score well in exams.

## Semiconductor Electronics: Materials, Devices And Simple Circuits Class 12 MCQs Questions with Answers

Number of electrons in the valence shell of a semiconductor is
(a) 1
(b) 2
(c) 3
(d) 4

With fall of temperature, the forbidden energy gap of a semiconductor
(a) increases
(b) decreases
(c) sometimes increases and sometimes decreases
(d) remains unchanged

The relation between number of free electrons (n) in a semiconductor and temperature (T) is given by:
(a) n ∝ T
(b) n ∝ T²
(c) n ∝ T1/2
(d) n ∝ T3/2

On applying reverse bias to a junction diode, it
(a) lowers the potential barrier
(b) raise the potential barrier
(c) increases the majority carrier current
(d) increases the minority carrier current

Answer: (b) raise the potential barrier

To obtain electrons as majority charge carriers in a semiconductors the impurity mixed is
(a) monovalent
(b) divalent
(c) trivalent
(d) pentavalent

In a common base amplifier the phase difference between the input signal voltage and output voltage is
(a) π/2
(b) 0
(c) π/4
(d) π

In binary system III represents
(a) 1
(b) 3
(c) 7
(d) 100

In a semiconductor, the forbidden energy gap between the valence band and the conduction band is of the order of
(a) 1 Mev
(b) 1 ev
(c) 0.1 Mev
(d) 5ev

In an n-p-n transistor circuit the collector current is 18 mA. If 90% of the electrons emitted reach the collector, than the emitter current is:
(a) 1.6 mA
(b) 16.4 mA
(c) 18 mA
(d) 20 mA

The part of the transistor which is heavily doped to produce a large number of majority carriers is
(a) emitter
(b) base
(c) collector
(d) none

An oscillator is an amplifier with
(a) a large gain
(b) Negative feedback
(c) positive feedback
(d) no feedback

How many AND gates are required to form, NAND gate?
(a) 0
(b) 1
(c) 2
(d) 4

Semiconductors of both p-type and n-type are produced by
(a) ionic solids
(b) covalent solids
(c) metallic solids
(d) molecular solids

In a p-type semiconductor, current conduction is by
(a) atoms
(b) holes
(c) electrons
(d) protons

On applying reverse bias to a junction diode, it
(a) lowers the potential barrier
(b) raise the potential barrier
(c) increases the majority carrier current
(d) increases the minority carrier current

Answer: (b) raise the potential barrier

p-n junction diode can be used as
(a) amplifier
(b) oscillator
(c) detector
(d) modulator

In semi conductor, at room temperature
(a) the valence bond is partially empty and the conduction band is partially filled
(b) the valence band is completely filled and the conduction band is partially filled
(c) the valence band is completely filled
(d) the conduction band is completely empty

Answer: (a) the valence bond is partially empty and the conduction band is partially filled

Energy bands in solids are a consequence of
(a) Ohm’s Law
(b) Pauli’s exclusion principle
(c) Bohr’s theory
(d) Heisenberg’s uncertainty principle

Which of following statements is not true?
(a) Resistance of an intrinsic semiconductor decreases with increase in temperature
(b) Doping pure Si with trivalent impurities gives p-type semiconductor
(c) The majority carriers in n-type semiconductor are holes
(d) A p-n junction can act as semiconductor diode

Answer: (c) The majority carriers in n-type semiconductor are holes

In principle, Boolean algebra is based on
(a) simple numbers
(b) binary numbers
(c) logic
(d) truth

What is the number of possible crystal systems?
(a) 5
(b) 7
(c) 14
(d) 16

A p-type semiconductor is
(a) negatively charged
(b) positively charged
(c) uncharged
(d) None of these

Crystal diode is
(a) amplifying device
(b) fluctuating device
(c) non-linear device
(d) linear device

Which of the following gate is not an universal gate?
(a) OR
(b) NOT
(c) AND
(d) NAND