The conductivity of a metal is determined by

by

1 Answer

Answer :

The conductivity of a metal is determined by the electronic concentration and the mobility of the free electrons.

by

Related questions

The conductivity of an extrinsic semiconductor with temperature

Last Answer : The conductivity of an extrinsic semiconductor with temperature remains constant.

Super conductivity can be destroyed by

Last Answer : Superconductivity can be destroyed by application of magnetic field.

The conductivity of a conductor can be increased by?

Description : The conductivity of a conductor can be increased by?

Last Answer : The conductivity of a conductor can be increased by decreasing its temperature.

In a crystal, an atom vibrates at a frequency determined by

Last Answer :  In a crystal, an atom vibrates at a frequency determined by the stiffness of the bonds it makes with neighbors.

Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre. (A) Electrical resistance (B) Thermal conductivity (C) Strength (D) None of these

Description : Psychrometry deals with the properties of gas-vapor mixture. Humidity can be determined by the measurement of the __________ of a fibre. (A) Electrical resistance (B) Thermal conductivity (C) Strength (D) None of these

Last Answer : (A) Electrical resistance

The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. (A) Viscosity (B) Density (C) Thermal conductivity (D) Corrosive nature

Description : The type of liquor circulation system to be ' employed in evaporators (viz. natural or forced circulation) is determined mainly by the __________ of the liquid. (A) Viscosity (B) Density (C) Thermal conductivity (D) Corrosive nature

Last Answer : (A) Viscosity

Superconducting metal in super conducting state has relative permeability of

Last Answer : Superconducting metal in superconducting state has a relative permeability of zero.

The resistivity of a metal is a function of temperature because

Last Answer : The resistivity of a metal is a function of temperature because the amplitude of vibration of the atoms varies with temperature.

By increasing impurity content in the metal alloy the residual resistivity always

Description : By increasing impurity content in the metal alloy the residual resistivity always

Last Answer : By increasing impurity content in the metal alloy the residual resistivity always increases.

The metal having the lowest temperature coefficient of resistance is

Description :  The metal having the lowest temperature coefficient of resistance is

Last Answer : The metal having the lowest temperature coefficient of resistance is gold.

Which of the following criterion is used for any metal to be used as a cooking material? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Description : Which of the following criterion is used for any metal to be used as a cooking material? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Last Answer : (3) Less thermal conductivity Explanation: A metal to be used as a cooking material should have less thermal conductivity.

Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties (3) A metal loses conductivity (4) Transmutation of metal occurs

Description : Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties (3) A metal loses conductivity (4) Transmutation of metal occurs

Last Answer : (2) A metal loses magnetic properties Explanation: In physics and materials science, the Curie temperature (TO, or Curie point, is the temperature at which a ferromagnetic or a ... in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.

The metal whose electrical conductivity is more, is – (1) copper (2) aluminium (3) silver (4) lead

Description : The metal whose electrical conductivity is more, is – (1) copper (2) aluminium (3) silver (4) lead

Last Answer : (3) silver Explanation: Copper ; 9% less conductive than silver: aluminium is 1 0% less conductive than copper; while steel is the least conductive among the given options. The most electrically conductive metal is silver.

Which of the following metal has maximum electrical conductivity?

Description : Which of the following metal has maximum electrical conductivity?

Last Answer : Silver

A bearing metal should not have (A) Enough plasticity (B) Low thermal conductivity (C) Low co-efficient of friction (D) High toughness

Description : A bearing metal should not have (A) Enough plasticity (B) Low thermal conductivity (C) Low co-efficient of friction (D) High toughness

Last Answer : (B) Low thermal conductivity

The electrical conductivity of a __________ decreases with rise in temperature. (A) Metal/alloy (B) Semi-conductor (C) Dielectric (D) None of these

Description : The electrical conductivity of a __________ decreases with rise in temperature. (A) Metal/alloy (B) Semi-conductor (C) Dielectric (D) None of these

Last Answer : (A) Metal/alloy

A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Description : A metallic alloy in general as compared to their pure metal components is (A) More corrosion resistant (B) Having higher melting point (C) Having lower hardness, reactivity and fusibility (D) Having lower electrical conductivity

Last Answer : (A) More corrosion resistant

A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Description : A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m2 .K. The Biot number is (A) 5.6 (B) 0.025 (C) 3.5 (D) 0.0035

Last Answer : (B) 0.025

The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k

Description : The variation of thermal conductivity of a metal with temperature is often correlated using an expression of the form K = K0 + at, where, K is the thermal conductivity and T is the temperature (in °K). The units of 'a' in SI system will be (A) W/m.k (B) W/m (C) W/m.k

Last Answer : (C) W/m.k

Finned tube heat exchangers (A) Give larger area per tube (B) Use metal fins of low thermal conductivity (C) Facilitate very large temperature drop through tube wall (D) Are used for smaller heat load

Description : Finned tube heat exchangers (A) Give larger area per tube (B) Use metal fins of low thermal conductivity (C) Facilitate very large temperature drop through tube wall (D) Are used for smaller heat load

Last Answer : (A) Give larger area per tube

What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Description : What is the critical radius of insulation (cms) for a metallic cylinder, if the convective heat transfer co-efficient with the ambient atmosphere is 5 W/m2. °K? Thermal conductivity of metal and insulation material are 40 and 0.1 W/m.°K respectively. (A) 2 (B) 8 (C) 10 (D) 40

Last Answer : (A) 2

Pick out the wrong statement. (A) Lead can creep under its own weight at room temperature (B) The electrical conductivity of gold is considerably reduced by alloying additions due to the decrease in electron movement (C) Recrystallisation temperature decreases with decrease in strain in a cold worked metal (D) With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase

Description : Pick out the wrong statement. (A) Lead can creep under its own weight at room temperature (B) The electrical conductivity of gold is considerably reduced by alloying additions due to ... metal (D) With increase in temperature, the electrical conductivity of intrinsic semi-conductor will increase

Last Answer : (C) Recrystallisation temperature decreases with decrease in strain in a cold worked metal

With increase in temperature, the electrical conductivity of a __________ decreases. (A) Semi-conductor (B) Metal or alloy (C) Dielectric (D) None of these

Description : With increase in temperature, the electrical conductivity of a __________ decreases. (A) Semi-conductor (B) Metal or alloy (C) Dielectric (D) None of these

Last Answer : (A) Semi-conductor

Which of the following is an undesirable property of slag produced during the Pyrometallurgical method of metal extraction from its ore? (A) High fusibility & fluidity (B) High thermal conductivity (C) Low density (D) High chemical activity

Description : Which of the following is an undesirable property of slag produced during the Pyrometallurgical method of metal extraction from its ore? (A) High fusibility & fluidity (B) High thermal conductivity (C) Low density (D) High chemical activity

Last Answer : B) High thermal conductivity

Pick out the wrong statement. (A) Copper is the metal having the highest electronic conductivity (B) Hardenability & Weldability of metals are inversely related (C) Covalent bonding formed by sharing of electrons is present in all semiconductor materials (D) Glass transition temperature applies to 'polymers' but not to 'glasses'

Description : Pick out the wrong statement. (A) Copper is the metal having the highest electronic conductivity (B) Hardenability & Weldability of metals are inversely related (C) Covalent bonding formed by ... all semiconductor materials (D) Glass transition temperature applies to 'polymers' but not to 'glasses'

Last Answer : Option A

The property due to which a metal can be hammered into thin sheets without breaking is _______. a) malleability b)ductility c)tensile strength d)conductivity

Description : The property due to which a metal can be hammered into thin sheets without breaking is _______. a) malleability b)ductility c)tensile strength d)conductivity

Last Answer : a) malleability

The property due to which the resistance of some metal or compound vanishes under certain conditions is (A) Semi conductivity. (B) Super conductivity. (C) Curie point. (D) Magnetostriction.

Description : The property due to which the resistance of some metal or compound vanishes under certain conditions is (A) Semi conductivity. (B) Super conductivity. (C) Curie point. (D) Magnetostriction.

Last Answer : (B) Super conductivity.

Which of the following criterion is used for any metal to be used as a cooking material ? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Description : Which of the following criterion is used for any metal to be used as a cooking material ? (1) More specific heat (2) More thermal conductivity (3) Less thermal conductivity (4) Less electrical conductivity

Last Answer : Less thermal conductivity 

The metal whose electrical conductivity is more, is (1) copper (2) aluminium (3) silver (4) lead

Description : The metal whose electrical conductivity is more, is (1) copper (2) aluminium (3) silver (4) lead

Last Answer : silver

Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties. (3) A metal loses conductivity (4) Transmutation of metal occurs.

Description : Curie point is the temperature at which (1) Matter becomes radioactive (2) A metal loses magnetic properties. (3) A metal loses conductivity (4) Transmutation of metal occurs.

Last Answer : A metal loses magnetic properties.

The coordination number of a central metal atom in a complex is determined by:

Description : The coordination number of a central metal atom in a complex is determined by:

Last Answer : The coordination number of a central metal atom in a complex is determined by: A. the number of ... ligands around a metal ion bonded by sigma bonds

Purity of a metal can be determined with the help of – (1) Pascal's law (2) Boyle's law (3) Archimedes principle (4) Conservation of mass principle

Description : Purity of a metal can be determined with the help of – (1) Pascal's law (2) Boyle's law (3) Archimedes principle (4) Conservation of mass principle

Last Answer : (3) Archimedes principle Explanation: Purity of a metal can be determined with the help of Archimedes Principle which makes use of the densities and buoyancy of metals. Finding the density of a metal ... help to determine its purity. It is most commonly used in the checking the purity of gold.

A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then which is correct statement about density of metal (A) Density of metal can't be determined (B) Metal is twice as dense as water (C) Metal will float in water (D) Metal is twice as dense as unknown fluid

Description : A sample of metal weighs 219 gms in air, 180 gms in water, 120 gms in an unknown fluid. Then  which is correct statement about density of metal  (A) Density of metal can't be determined  (B) ... as water  (C) Metal will float in water  (D) Metal is twice as dense as unknown fluid 

Last Answer : (A) Density of metal can't be determined 

Purity of a metal can be determined with the help of (1) Pascal’s law (2) Boyle’s law (3) Archimedes principle (4) Conservation of mass principle

Description : Purity of a metal can be determined with the help of (1) Pascal’s law (2) Boyle’s law (3) Archimedes principle (4) Conservation of mass principle

Last Answer : Archimedes principle

Ferromagnets

Description : Ferromagnets

Last Answer : Ferromagnets Only certain materials, such as iron, cobalt, nickel, and gadolinium, exhibit strong magnetic effects. Such materials are called ferromagnetic, after the Latin word for iron, ... licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.

The attraction capacity of electromagnet will increase if the

Last Answer : Atrraction  capacity  will  increase  if  supply  current  is  increased.

Temporary magnets are used in

Last Answer : Temporary magnets are used in loud-speakers,generators, motors.

Main causes of noisy solenoid are

Last Answer : Main causes of noisy solenoid are strong tendency of fan out of laminations at the end caused by repulsion among magnetic lines of force, uneven bearing surface, caused by dirt or uneven wear between moving and stationary parts.

Core of an electromagnet should have

Last Answer : Core of an electromagnet should have low coercivity, high susceptibility.

Magnetism of a magnet can be destroyed by

Last Answer : Magnetism of a magnet can be destroyed by heating, hammering, by inductive action of another magnet.

The magnetic materials exhibit the property of magnetisation because of

Last Answer : The magnetic materials exhibit the property of magnetisation because of spin of nucleus.

The bar magnet has

Last Answer : The bar magnet has the dipole moment.

The stray line of magnetic flux is defined as

Last Answer : The stray line of magnetic flux is defined as a line of magnetic flux which does not follow the designed path.

How does the magnetic compass needle behave in a magnetic field ?

Last Answer : It assures a position which follows a line of magnetic flux

The initial permeability of an iron rod is

Last Answer : The initial permeability of an iron rod is the permeability almost in non-magnetised state.

The magnetic reluctance of a material

Last Answer : The magnetic reluctance of a material decreases with increasing cross-sectional area of the material.

The magneto-motive force is

Last Answer : The magneto-motive force is the sum of all currents embraced by one line of magnetic field.

The uniform magnetic field is

Last Answer : The uniform magnetic field is the field in which all lines of magnetic flux are parallel and equidistant.

Magnetic moment is a

Last Answer : Magnetic moment is a vector quantity.

A keeper is used to

Last Answer : A keeper is used to provide a closed path for flux.