The molecules in a solid move
In a random manner
In a haphazard way
In circular motion
Back and forth like tiny pendulums
Correct Answer :
D. Back and forth like tiny pendulums
Related Questions
In spheroidising process, the steel is
Heated below the lower critical temperature and then cooled slowly
Heated up to the lower critical temperature and then cooled in still air
Heated slightly above the lower critical temperature and then cooled slowly to a temperature of 600°C
None of the above
Bell metal contains
70% copper and 30% zinc
90% copper and 10% ti
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
Which of the following property is desirable for materials used in tools and machines?
Elasticity
Plasticity
Ductility
Malleability
Which of the following statement is incorrect about duralumin?
It is prone to age hardening
It can be forged
It has good machining properties
It is lighter than pure aluminium
Connecting rod is, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
High speed steel
Manganese in steel increases its
Tensile strength
Hardness
Ductility
Fluidity
Aluminium bronze contains
94% aluminium, 4% copper and 0.5% Mn, Mg, Si and Fe
92.5% aluminium, 4% copper, 2% nickel, and 1.5% Mg
10% aluminium and 90% copper
90% magnesium and 9% aluminium with some copper
Large forgings, crank shafts, axles normally contain carbon up to
0.05 to 0.20 %
0.20 to 0.45 %
0.45 to 0.55 %
0.55 to 1.0 %
Super conduction by metals is observed in the temperature range of
Below 10°K
Above 100°K
Around 0°C
Around 100°C
Which is the false statement about wrought iron? It has
High resistance to rusting and corrosion
High ductility
Ability of hold protective coating
Uniform strength in all directions
Shock resistance of steel is increased by adding
Nickel
Chromium
Nickel and chromium
Sulphur, lead and phosphorus
Balls for ball bearings are made of
Cast iron
Mild steel
Stainless steel
Carbonchrome steel
Basic solution is one which has pH value
Greater than 7
Equal to 7
Less than 7
pH value has nothing to do with basic solution
Cast iron is characterised by minimum of following percentage of carbon
0.2 %
0.8 %
1.3 %
2 %
The usual composition of a soldering alloy is
Tin, lead and small percentage of antimony
Tin and lead
Tin, lead and silver
Tin and copper
Brass contains
70% copper and 30% zinc
90% copper and 10% tin
85 - 92% copper and rest tin with little lead and nickel
70 - 75% copper and rest tin
Solder is an alloy consisting of
Tin, antimony, copper
Tin and copper
Tin and lead
Lead and zinc
Which of the following impurity in cast iron makes it hard and brittle?
Silicon
Sulphur
Manganese
Phosphorus
In process annealing, the hypo eutectoid steel is
Heated from 30°C to 50°C above the upper critical temperature and then cooled in still air
Heated from 30°C to 50°C above the upper critical temperature and then cooled suddenly in a suitable cooling medium
Heated from 30°C to 50°C above the upper critical temperature and then cooled slowly in the furnace
Heated below or closes to the lower critical temperature and then cooled slowly
Specify the sequence correctly
Grain growth, recrystallisation, stress relief
Stress relief, grain growth, recrystallisation
Stress relief, recrystallisation, grain growth
Grain growth, stress relief, recrystallisation
Connecting rod is usually made of
Aluminium
Low carbon steel
Medium carbon steel
High carbon steel
Nodular iron has
High machinability
Low melting point
High tensile strength
All of the above
In nodular iron, graphite is in the form of
Cementite
Free carbon
Flakes
Spheroids
The composition of silver solder is
Silver, copper, zinc
Silver, tin, nickel
Silver, lead, zinc
Silver, copper, aluminium
Eutectoid steel consists of
Wholly pearlite
Wholly austenite
Pearlite and ferrite
Pearlite and cementite
German silver is an alloy of
Silver and some impurities
Refined silver
Nickel, Copper and zinc
Nickel and copper
Annealing of white cast iron results in production of
Malleable iron
Nodular iron
Spheroidal iron
Grey iron
Lead is poured into the joint between two pipes. These pipes may be made of
Cast iron
Vitrified clay
Asbestos cement
Concrete
Delta iron occurs at temperature of
Room temperature
Above melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
Tungsten in steel
Improves wear resistance, cutting ability and toughness
Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties
Improves cutting ability and reduces hardenability
Gives ductility, toughness, tensile strength and anticorrosion properties