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WorksheetsEE materials
Total questions: 20
Worksheet time: 7mins
Which of the following variety of copper has the best conductivity ?
Induction hardened copper
Hard drawn copper
Pure annealed copper
Copper containing traces of silicon
________ has the best damping properties.
Diamond
High speed steel
Mild steel
Cast iron
_______ is a hard solder.
Tin-lead
Tin-silver-lead
Copper-zinc
None of the above
Spark plug makes use of which of the following materials for insulation ?
Porcelain
Slate
Asbestos
Glass
An H.R.C. fuse is
A ceramic body having metal and caps
A wire of platinum
A heavy cross-section of copper or aluminium
A ceramic tube having carbon rod inside it
Which of the following materials is used for making coils of
standard resistances ?
Copper
Nichrome
Platinum
Manganin
High resistivity materials are used in
Precision instruments
Heating elements
Motor starters
Incandescent lamps
All of the above
Low resistivity materials are used in
Transformer, motor and generator windings
Transmission and distribution lines
House wiring
All above applications
Which of the following affect greatly the resistivity of
electrical conductors?
Composition
Pressure
Size
Temperature
Which of the following resistive materials has the lowest
temperature co-efficient of resistance ?
Nichrome
Constantan
Kanthal
Molybdenum
Substances whose specific resistance abruptly decreases at very low temperature are called
Insulators
Conductors
Semiconductors
Superconductors
The impurity atoms is semiconductors
Inject more charge carriers
Reduce the energy gap
Increase the kinetic energy of valence electrons
All of the above
A good electric contact material should have all of the following properties except
High resistivity
High resistance to corrosion
Good thermal conductivity
High melting point
Which of the following materials is preferred for transmitting electrical energy over long distance ?
Copper
Aluminium
Steel reinforced copper
Steel reinforced aluminium
Choose the best suitable of Diamagnetic : Paramagnetic::
Water : Air.
Iron : Steel.
Permalloy : Super-alloy.
Nickel : Cobalt.
When a ferromagnetic substance is magnetized small changes in dimensions occur. Such a phenomenon is known as
magnetostriction.
magnetic hysteresis.
magneto-calorisation.
magnetic expansion.
A material with unequal anti-parallel atomic magnetic moments is
ferrimagnet.
an anti-ferromagnet.
a ferrite.
non-magnetic.
What are insulating materials that can tolerate maximum temperature?
Mica.
Porcelain.
Glass.
All of these.
Find the odd one out.
Absorptivity.
Emissivity.
Refractive index.
Dielectric strength.
Substance having permeability less than the permeability of free space, are known as
ferromagnetic.
bipolar.
paramagnetic.
diamagnetic.
