The rule that resistivity of conductors can be separated into two parts viz. temperature independent and temperature dependent is known as
Q.2.
When a material is in superconducting state and a magnetic field is applied
The superconducting property is not affected
The superconducting property may be affected and resistivity may increase from zero to a low value
The superconducting property may be destroyed
The material may become an insulator
Q.3.
The unit for mmf is
A
Wb
T
V
Q.4.
When a dielectric material is subjected to alternating field, the absorption of energy by the material from the field is given by the imaginary part of polarizability.
True
False
Q.5.
The phenomenon of dielectric hysteresis occurs with
DC
AC
Both AC and DC
None of the above
Q.6.
Hall effect is observed in a specimen (metal or semi conductor) when it is carrying current and is placed in a magnetic field. The resultant electric field inside the specimen is
Normal to both current and magnetic field
In the same direction as current
In a direction anti parallel to magnetic field
None of the above
Q.7.
As the atoms of rare gases become larger, electronic polarizability
Increases
Decreases
Remains the same
May increase or decrease
Q.8.
The residual resistivity of a binary alloy at 0 K is
Sum of residual resistivities of component metals
Difference of residual resistivities of component metals
Product of residual resistivities of component metals
Dependent on the concentration of minor component in the alloy
Q.9.
Nickel is a non-magnetic material.
True
False
Q.10.
The most important set of specifications of transformer oil include
dielectric strength and viscosity
dielectric strength and flash point
viscosity and flash point
flash point and viscosity
Q.11.
If a small amount of Cu is added to Ni conductor, then
Resistivity of Ni will decrease at all temperatures because Cu is a better conductor than Ni
Residual resistivity of Ni at low temperature will increase as Cu atoms act as defect centres
Resistivity of Ni will increase at all temperatures as Cu destroys the periodicity of Ni and acts as defects
Resistivity of Ni remains the same
Q.12.
The fact that domains exhibits spontaneous magnetisation is
First hypothesis is of Curie
Second hypothesis is of Weiss
Curie-Weiss law
Boltzmann’s statistics
Q.13.
The number of protons in a silicon atom are
4
8
12
14
Q.14.
The elements which become superconducting at extremely low temperatures are
Good conductors at room temperature
Ferromagnetic at room temperature
Relatively poor conductors at room temperature
Insulators at room temperature
Q.15.
If the number of atoms per unit volume of a monoatomic gas changes, the dielectric constant still remains constant.
True
False
Q.16.
With increase in temperature, the electrical conductivity would
Increase in metals as well as in intrinsic semiconductor
Increase in metals but decrease in intrinsic semiconductor
Decrease in metals but increase in intrinsic semiconductor
Decrease in metals as well as in intrinsic semiconductor
Q.17.
The number of protons in a copper atom are
2
9
11
29
Q.18.
Wood is a diamagnetic material.
True
False
Q.19.
In a metal, the valence electrons
Are not shared
Are shared only between neighbouring atoms
Are shared by all atoms
Either B or C
Q.20.
Ferrimagnetic materials have anti parallel orientation of equal moments of permanent dipoles.
True
False
Support mcqgeeks.com by disabling your adblocker.
Please disable the adBlock and continue. Thank you.