When a wire loop is rotated in a magnetic field the direction of the induced emf changes one in every _______ revolution
Correct Answer :
B.
Related Questions
If the length and area of cross-section of a wire are doubleda then its resistance
becomes four times
becomes sixteen times
remains the same
becomes two times
The resistivity of a conductor ___________ with an increase in temperature.
increases
decreases
remains the same
becomes zero
The temperature coefficient of resistance of semiconductors is
positive
zero
negative
infinite
One of the solid structures in which the position of the atoms or ions are predetermined
Crystalline solid
Amorphous solid
Polycrystalline solid
Poly amorphous solid
If you hold the conductor with right hand so that the stretched thumb points in the direction of the currenta then encircling fingers will give the direction of magnetic lines of force round the conductor. This is known as
Left hand cork screw rule
Right hand cork screw rule
Left hand rule
Right hand rule
The magnetic energy stored in an inductor is ______ current.
Directly proportional to
Inversely proportional to
Directly proportional to the square of
Inversely proportional to the square of
The force of attraction or repulsion between two magnetic poles is directly proportional to their strengths.
Newton's first law
Faraday's first law of electromagnetic induction
Coulomb's first law
Coulomb's second law
The lagging effect between flux density of the material and the magne
Permeance
Eddy current
Hysteresis
R eluctance
Which of the following magnetic materials can be easily magnetized in both direction?
Soft magnetic materials
Hard magnetic materials
High hysteresis loss materials
Low hysteresis loss materials
The physical motion resulting from the forces of magnetic fields is called
Motor action
Rotation
Repulsion
Torque action
The temperature coefficient of resistance of conductors is
positive
zero
negative
infinite
What is the usual value of leakage coefficient for electrical machines?
0.5 to 1
1 to 5
5 to 10
1.15 to 1.25
The resistance of a material is ____________ its area of cross-section.
directly proportional
independent of
inversely proportional to
equal to
A magnetizing force of 1000 AT/m will produce a flux density of __________ i
1.257 mWb/m^2
0.63 Wb/m^2
1.257 Wb/m^2
0.63 mWb/m^2
What determines the atomic number of an element?
The number of protons
The number of electrons
The number of neutrons
The number of neutrons and protons
How many electrons are needed in the valence orbit to give a material's stability?
At/m is a unit of
mmf
magnetic force
reluctance
magnetic flux density
The phenomenon by which a magnetic substance becomes a magnet when it is place near a magnet
Magnetic effect
Magnetic phenomenon
Magnetic induction
Electromagnetic induction
What is the SI unit of conductance?
Siemens
Mhos
Ohms
1/Ohms
The emf induced in a coil due to the changing current of another neighboring coil is called
Mutually induced emf
Self induced emf
Statically induced emf
Dynamically induced emf
One oersted (Oe) is equivalent to _____ Gb/cm.
The contribution to the ionization in an ionization chamber by electrons liberated from t he walls.
Skin effect
Walt effect
Hall effect
Edison effect
Which of the following materials has the least hysteresis loop area?
soft iron
silicon steel
hard steel
wrought iron
A factor used to correct for the electrostatic forces of the more distant ions in an ionic solid.
Avogadro's number
Planck's constant
Boltzmann's constant
Madelung constant
Electromotive force in a circuit
causes free electrons to flow
increases the circuit resistance
maintains circuit resistance
is needed to make the circuit complete
Electrons at the outer shell are called
Outer shell electrons
Inner shell electrons
Semiconductor electrons
Valence electrons
The science of adapting electronics to aerospace flight.
Avionics
Aerotronics
Aerodynamics
Astrionics
An electron- volt (eV) is a unit of
Energy
Potential difference
Charge
Momentum
If the right handed bottle-opener cork screw is assumed to be along the conductor so as to advance in the direction of current flow, the motion of its handle will indicate the direction of magnetic flux produced around the conductor. This is known as
Right hand rule
Left hand rule
Cork screw rule
End rule
A 6- V battery is connected across a solenoid of 100 turns having a resistance of 2 ?a Calculate the number of ampere turns?