Home
Current Affairs January 2024

What is the correct answer?

4

Theory of ferromagnetic phenomena which assumes each atom is a permanent magnet which can turn freely about its center under the influence of applied field and other magnets.

A. Ewing's theory of ferromagnetism

B. Oersted's ferromagnetism theory

C. Maxwell's magnetic theory

D. Ampere's circuital law

Correct Answer :

A. Ewing's theory of ferromagnetism


Related Questions

What is the correct answer?

4

An atom or a group of atoms that carries a net electric charge.

A. Positive ion

B. Negative ion

C. Ion

D. Electron

What is the correct answer?

4

Used to maintain strength of magnetic field

A. Container

B. Air gap

C. Keeper

D. S ource

What is the correct answer?

4

When the current flowsa the magnetic field ��. conductor is in what direction?

A. The same as the current direction

B. Opposite the current direction

C. Omnidirectional

D. In the direction determined by the left hand rule

What is the correct answer?

4

The force acting on a unit n- pole placed at that point is called

A. Magnetic field intensity

B. Electric field intensity

C. Electromagnetic field intensity

D. Intensity magnetization

What is the correct answer?

4

The induced emf in a wire loop that is moved parallel to a uniform magnetic field is

A. Zero

B. Dependent on the area of the loop

C. Dependent on the shape of the loop

D. Dependent on the magnitude of the field

What is the correct answer?

4

Which of the following has the highest permeability?

A. Soft iron

B. Steel

C. Air

D. Permalloy

What is the correct answer?

4

If the length and area of cross-section of a wire are doubleda then its resistance

A. becomes four times

B. becomes sixteen times

C. remains the same

D. becomes two times

What is the correct answer?

4

If two similar charges 1 coulomb each are placed 1 m apart in aira then the force of repulsion is

A. 8 × 10^6 N

B. 9 × 10 ^9 N

C. 10^6 N

D. 5 × 10^6 N

What is the correct answer?

4

A magnetic material losses its ferromagnetic properties at a point called

A. Curie temperature

B. Inferred absolute temperature

C. Room temperature

D. Absolute temperature

What is the correct answer?

4

The relation between absolute permittivity of air ( 0)a absolute p and velocity of light (c) is given by

A. 0 0= c^2

B. 0 0= c

C. 1/ 0 0= c

D. 1/ 0 0= c^2

What is the correct answer?

4

A principle that states that only two electrons with different spins are allowed to exist in a given orbit

A. Bohr's principle

B. Pauli exclusion principle

C. Avogadro's principle

D. Coulomb's principle

What is the correct answer?

4

Two similar polesa each 1Wba placed 1 m apart in air will experience a repulsive force of

A. 63000 N

B. 63 × 10^-3 N

C. 8 × 10^12 N

D. 796 kN

What is the correct answer?

4

What is the typical saturation flux density for most magnetic materials?

A. 4 Wb/m^2

B. 5 Wb/m^2

C. 1 Wb/m^2

D. 2 Wb/m^2

What is the correct answer?

4

The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as

A. Retentivity

B. Reluctivity

C. Resistivity

D. Conductivity

What is the correct answer?

4

What is the SI unit of reluctance?

A. At

B. At/m

C. N/Wb

D. At/Wb

What is the correct answer?

4

The science of adapting electronics to aerospace flight.

A. Avionics

B. Aerotronics

C. Aerodynamics

D. Astrionics

What is the correct answer?

4

Referred to as the specific reluctance of a material

A. Resistivity

B. Reluctivity

C. Conductivity

D. Permeability

What is the correct answer?

4

The unit of flux is _____ in cgs system.

A. Tesia

B. Gilbert

C. Maxwell

D. Oersted

What is the correct answer?

4

There are how many compounds available in nature?

A.

B.

C. 300a000

D. Unlimited

What is the correct answer?

4

Steel is hard to magnetize because of its

A. Low permeability

B. High permeability

C. High density

D. High retentivity

What is the correct answer?

4

If on looking at any one end of a solenoid; the direction of current flow is found to be clockwise then the end under observation is a south pole. This is known as

A. Right hand rule

B. Left hand rule

C. Cork screw rule

D. End Rule

What is the correct answer?

4

A good conductor has how many valence electrons?

A.

B.

What is the correct answer?

4

Materials whose permeabilities are slightly greater than that of free space

A. Paramagnetic

B. Non- magnetic

C. Ferromagnetic

D. Diamagnetic

What is the correct answer?

4

The magnetic field inside a solenoid

A. is zero

B. is uniform

C. increases with distance from the axis

D. decreases with distance from the axis

What is the correct answer?

4

A one cubic cm of copper has how many free electrons at room temperature?

A. 80 × 10^18

B. 8.5 × 10^22

C. 20 × 10^10

D. 50 × 10^20

What is the correct answer?

4

Which of the following has the least number of valence electrons?

A. Conductor

B. Semiconductor

C. Insulator

D. Semi- insulator

What is the correct answer?

4

If the resistance of a material 2 m long and 2 m^2 in area of cross-section is 1.6 ×10^-8 ?a then its resistivity is

A. 3.2 × 10^-8 ?-m

B. 1.6 × 10^-8 ?-m

C. 0.64 × 10^-8 ?-m

D. 0.16 × 10^-8 ?-m

What is the correct answer?

4

The branch of Engineering which deals with the magnetic effect of electric current is known as

A. Magnetism

B. Electromagnetism

C. Electrical engineering

D. Electronics engineering

What is the correct answer?

4

Which element has four valence electrons?

A. Conductor

B. Insulator

C. Semiconductor

D. Semi- insulator

What is the correct answer?

4

What is the SI unit of conductance?

A. Siemens

B. Mhos

C. Ohms

D. 1/Ohms