The resistivity of a conductor ___________ with an increase in temperature.
increases
decreases
remains the same
becomes zero
Correct Answer :
A. increases
Related Questions
What is the cgs unit of magnetomotive force?
Gilbert
Ampere- turn
Maxwell
Weber
The property of magnetic materials of retaining magnetism after withdrawal of the magnetizing force is known as
Retentivity
Reluctivity
Resistivity
Conductivity
One coulomb of charge consists of ________ electrons.
624× 10^16
62.4 × 10^16
6.24 × 10^16
0.624 × 10^16
A magnetic field is
The current flow through space around a permanent magnet
The force set up when current flows through a conductor
The force that drives current through a resistor
The force between the plates of a charged capacitor
A substance that attracts pieces iron
Conductor
Semiconductor
Magnet
All of the above
The idea of preventing one component from affecting another through their common electric and magnetic field is referred to as
Hall effect
Grounding
Shielding
Limiting
What is the relative permittivity of air?
8.854 × 10^-12
4 × 10^7
How many turns are needed to produce a magnetomotive force of 1000 A.t for a coil with 6 amperes?
6000 turns
600 turns
167 turns
67turns
The force between two magnetic poles is _____ their poles strength.
equal to
directly proportional to
inversely proportional to
directly proportional to the square root of
A magnetic circuit carries a flux iin the iron part and a fluxgin the air gap. What is the leakage coefficient?
i/g
i × g
g/ i
i + g
Hysteresis refers to the ______ between flux density of the material and the magnetizing force applied.
Leading effect
Ratio
Equality
Lagging effect
At/m is a unit of
mmf
magnetic force
reluctance
magnetic flux density
Magnetic intensity is a
Phasor quantity
Physical quantity
Scalar quantity
Vector quantity
The emf produced in a wire by its motion across a magnetic field does not depend upon the
Diameter of the wire
Length of the wire
Orientation of the wire
Flux density of the field
Temporary magnets are commonly employed in
electric instruments
motors
moving coils loudspeakers
magnetos
Small voltages generated by a conductor with current in an external magnetic field.
Skin effect
Magnetic effect
Hall effect
Flywheel Effect
All matters (gasa liquid and solid) are composed of
Neutrons
Particles
Electrons
Atoms
The net electrical charge in an isolated system remains constant. This is known as
Law of conservation of charge
Coulomb's first law
Coulomb's second law
Law of conservation of energy
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
Amorphous solid is also called
Crystalline
Non- crystalline
Polycrystalline
Homogenous
The straight line passing through the two poles of magnet is called
Real axis
Cartesian axis
Magnetic axis
Imaginary axis
Another term for corona discharge.
Lightning
Sparking
Aurora
Corona Effect
Which of the following has the least number of valence electrons?
Conductor
Semiconductor
Insulator
Semi- insulator
What type of bond is formed when there exists some form of collective interactions between the (negatively charged) electrons and (positively charged) nuclei in a solid?
Ionic
Covalent
Metallic
Van der Waals
A positively charged body has
deficit of electrons
excess of neutrons
excess of electrons
deficit of protons
Refers to the non- metallic materials that have the ferromagnetic properties of iron.
Ferrites
Ferromagnetic
Diamagnetic
Paramagnetic
Whenever a flux inking a coil or current changesa an emf is induced in it. This is known as
Joule's Law
Coulomb's Law
Faraday's first law of electromagnetic induction
Faraday's second law of electromagnetic induction
If the relative permittivity of a material is 10a then its permittivity is
4 × 10^7F/m
4 × 10^-6 F/m
8.854× 10^-11 F/m
8.854 × 10^-12 F/m
The potential at a point due to a charge is 15 V. If the distance is times, the potential at the point will be
5 V
18 V
45 V
15 V
Defined as the ratio of the volume occupied by the atoms or ions in a unit cell divided by the volume of the unit cell and is used to measure the compactness of a crystal.
Atomic packing factor (APF)
Ionic Packing Ratio (IPR)
Atomic compacting factor (ACF)
Ionic compacting ratio (ICR)