Tuesday, 1 November 2016

Filled Under:

ELECTRONICS AND COMMUNICATION ENGINEERING IMPORTANT MCQ-ELECTRICITY AND MAGNETISM FUNDAMENTALS (PART THREE)

104.An alloy of 40 percent iron and 60 percent nickel.
A. Alnico
B. Permalloy
C. Hipernik
D. Manganin
105. A commercial alloy of aluminum nickel, and iron with cobalt, copper and titanium
added to produce about 12 grades.
A. Alnico
B. Brass
C. Aluminum
D. Constantan
106. The idea of preventing one component from affecting another through their common
electric and magnetic field is referred to as
A. Hall effect
B. Grounding
C. Shielding
D. Limiting
107. The physical motion resulting from the forces of magnetic fields is called
A. Motor action
B. Rotation
C. Repulsion
D. Torque action
108. Flux linkages equals
A. Flux times area of core
B. Flux times number of turns times area of core
C. Flux times number of turns times length of core
D. Flux times number of turns
109. Which of the following is a vector quantity?
A. Magnetic potential
B. Magnetic field intensity
C. Magnetic permeability
D. Flux density
110. Which of the following electric quantities is vector in character?
A. Field
B. Charge
C. Energy
D. Potential Difference
111. The quantity 10^6 maxwells is equivalent to one
A. Weber
B. Gauss
C. Gilbert
D. Tesla
112.What is the unit of reluctance?
A. Maxwell
B. Gauss
C. At/Wb
D. Weber
113.What is the SI unit of magnetic flux?
A. Tesla
B. Weber
C. Maxwell
D. Gauss
114.What is the unit of magnetomotive force?
A. Volt
B. Tesla
C. Ampere- turn
D. Weber
115. What is the cgs unit of magnetomotive force?
A. Gilbert
B. Ampere- turn
C. Maxwell
D. Weber
116. The unit of flux is _____in cgs system.
A. Tesia
B. Gilbert
C. Maxwell
D. Oersted
117. Flux density is measured in
A. Tesia
B. Weber
C. Ampere- turn
D. Maxwell
118. The customary energy unit in atomic and nuclear physics is
A. Joule
B. Volt- coulomb
C. electron-volt
D. Walt- second
119. One ampere- turn is equivalent to___ gilberts
A. 1.16
B. 1.26
C. 1.36
D. 1.46
120. The magnetic flux of 2000 lines is how many Maxwells?
A. 1000
B. 2000
C. 4000
D. 8000
121. How much is the flux in Weber in the above problem?
A. 2 x 10^-5
B. 2 x 10^-3
C. 2 x 10^5
D. 2 x 10^3
122. One oersted (Oe) is equivalent to ____Gb/cm.
A. 1
B. 10
C. 100
D. 1000
123. One electron volt (1 eV) is equivalent to _____joules
A. 1.3 x 1O^-19
B. 1.4 x 1O^-19
C. 1.5 x 1O^-19
D. 1.6 x 10^-19
124.An electron- volt (eV) is a unit of
A. Energy
B. Potential difference
C. Charge
D. Momentum
125. The unit of electrical energy is
A. Joule
B. Watt- second
C. Kilowatt- hour
D. All of these
126. Electrons at the outer shell are called
A. Outer shell electrons
B. Inner shell electrons
C. Semiconductor electrons
D. Valence electrons
127. Which of the following has the least number of valence electrons?
A. Conductor
B. Semiconductor
C. Insulator
D. Semi- insulator
128. A good conductor has how many valence electrons?
A. 1
B. 4
C. 2
D. 8
129. Which element has four valence electrons?
A. Conductor
B. Insulator
C. Semiconductor
D. Semi- insulator
130. A negative ion results when an atom gains an additional
A. Electron
B. Proton
C. Neutron
D. Atom
131. An atom or a group of atoms that carries a net electric charge.
A. Positive ion
B. Negative ion
C. Ion
D. Electron
132. Hysteresis refers to the_____ between flux density of the material and the magnetizing force applied.
A. Leading effect
B. Ratio
C. Equality
D. Lagging effect

133.Hydrogen is an example of a _________material.
A. Paramagnetic
B. Diamagnetic
C. Ferromagnetic
D. Non- magnetic
134.Cobalt is an example of a ____material.
A. Paramagnetic
B. Diamagnetic
C. Ferromagnetic
D. Non- magnetic
135. The evaporation of electrons from a heated surface is called
A. Radiation
B. Convection
C. Thermionic emission
D. Conduction
136. Electron is a Greek word for
A. amber
B. Fire
C. Stone
D. Heat
137. Gases whose particles are charged are known as
A. Conductors
B. Insulators
C. Gaseous Conductors
D. Plasma
138. What principle states that each electron in an atom must have a different set of quantum
numbers?
A. Inclusion principle
B. Exclusion principle
C. Quantum principle
D. Electron principle
139. The energy stored in an electrostatic field or electromagnetic field is called
A. Electromagnetic energy
B. Kinetic energy
C. Potential energy
D. Rest energy
14O. Which of the following statements is TRUE?
A. Silicon dioxide is a good
B. The current carriers in conductors are valence electrons
C. For conductors, the valence electron are strongly attracted to the nucleus
D. The valence electrons are located in the nucleus of an atom
141.How many electrons are needed in the valence orbit to give a material’s stability?
A. 8
B. 4
C. 6
D. 5
142. Residual magnetism refers to the flux density, which exists in the iron core when the
magnetic field intensity is
A. Minimized
B. Reduced to zero
C. Maximize
D. Unity
143.Magnetic intensity is a
A. Phasor quantity
B. Physical quantity
C. Scalar quantity
D. Vector quantity
144. The core of a magnetic equipment uses a magnetic material with
A. Least permeability
B. Low permeability
C. Moderate permeability
D. High permeability
145.Which of the following is a paramagnetic material?
A. Carbon
B. Copper
C. Bismuth
D. Oxygen
146. The permeability of permalloy is
A. Very much greater than permeability of air
B. Slightly greater than permeability of air
C. Slightly less than permeability of air
D. Equal to the permeability of air
147.A t/m is a unit of
A. Mmf
B. Emf
C. Reluctance
D. Magnetizing force
148. The force between two magnetic poles is____ their poles strength.
A. equal to
B. directly proportional to
C. inversely proportional to
D. directly proportional to the square root of
149. The magnetic energy stored in an inductor is ______current.
A. Directly proportional to
B. Inversely proportional to
C. Directly proportional to the square of
D. Inversely proportional to the square of
150.One of the common application of an air- cored choke.
A. Radio frequency
B. Audio frequency
C. Power supply
D. Power transformer
151.How is mutual inductance between two coils decreased?
A. By using a common core
B. By moving the coils closer
C. By moving the coils apart

D. By increasing the number of turns of either coil
TO DOWNLOAD PDF CLICK HERE

0 comments:

Post a Comment