The transistor is made of
Silver
Gold
Copper
Germanium
Correct Answer :
D. Germanium
Related Questions
Babbitt metal is a
Lead base alloy
Tin base alloy
Copper base alloy
Both (A) and (C) above
The material in which the atoms are arranged regularly in some directions but not in others, is called
Amorphous material
Mesomorphous material
Crystalline material
None of these
The machinability of steel is improved by adding
Nickel
Chromium
Nickel and chromium
Sulphur, lead and phosphorus
Which of the following steel making process is being adopted at Rourkela (in India) Steel Plant?
Bessemer process
Open hearth process
Electric process
LD process
In the lower part of the blast furnace (zone of fusion), the temperature is
400° to 700°C
800°C to 1000°C
1200°C to 1300°C
1500°C to 1700°C
Ball bearings are, usually, made from
Low carbon steel
High carbon steel
Medium carbon steel
Chrome steel
Free cutting steels
Are used where ease in machining is the criterion
Contain carbon in free form
Require least cutting force
Do not exist
Pearlite is a combination of
Ferrite and cementite
Cementite and gamma iron
Ferrite and austenite
Ferrite and iron graphite
The correct composition of Babbitt metal is
87.75% Sn, 4% Cu, 8% Sb, 0.25% Bi
90% Sn, 2% Cu, 4% Sb, 2% Bi, 2% Mg
87% Sn, 4% Cu, 8% Sb, 1% Al
82% Sn, 4% Cu, 8% Sb, 3% Al, 3% Mg
The ultimate tensile strength and yield strength of most of the metals, when temperature falls from 0 to 100°C will
Increase
Decrease
Remain same
First increase and then decrease
German silver contains
1% silver
2.5% silver
5% silver
10% silver
Which of the following is added in low carbon steels to prevent them from becoming porous?
Sulphur
Phosphorus
Manganese
Silicon
Permalloy is a
Kind of stainless steel
None ferrous alloy
Polymer
Nickel and iron alloy having high permeability
When steel containing less than 0.8% carbon is cooled slowly from temperatures above or within the critical range, it consists of
Mainly ferrite
Mainly pearlite
Ferrite and pearlite
Pearlite and cementite
Ductility of a material can be defined as
Ability to undergo large permanent deformations in compression
Ability to recover its original form
Ability to undergo large permanent deformations in tension
All of the above
The hardness of steel depends upon the
Amount of cementite it contains
Amount of carbon it contains
Contents of alloying elements
Method of manufacture of steel
Gamma iron exits at following temperature
Room temperature
Near melting point
Between 1400°C and 1539°C
Between 910°C and 1400°C
Sulphur in pig iron tends to make it
Hard
Soft
Ductile
Tough
Which of the following has highest specific strength of all structural materials?
Magnesium alloys
Titanium alloys
Chromium alloys
Magnetic steel alloys
The defect which takes place due to imperfect packing of atoms during crystallisation is known as
Line defect
Surface defect
Point defect
None of these
Hardness of lower bainite (tempered martensite) is about
RC 65
RC 48
RC 57
RC 80
Heavy duty leaf and coil springs contain carbon of the following order
0.2 %
0.5 %
0.8 %
1.0 %
When elements like nickel, chromium, copper and molybdenum are added to the molten cast iron, it produces
White cast iron
Nodular cast iron
Malleable cast iron
Alloy cast iron
Carbon steel is
Made by adding carbon in steel
Refined from cast iron
An alloy of iron and carbon with varying quantities of phosphorus and sulphur
Extensively used for making cutting tools
Manganese is added in low carbon steel to
Make the steel tougher and harder
Raise the yield point
Make the steel ductile and of good bending qualities
All of the above
Babbitt metal is a
Lead base alloy
Copper base alloy
Tin base alloy
Cadmium base alloy
Which of the following when used in ordinary low carbon steels, makes the metal ductile and of good bending qualities?
Sulphur
Phosphorus
Manganese
Silicon
The percentage of carbon in low carbon steel is
0.05 %
0.15 %
0.3 %
0.5 %
The composition of silver solder is
Silver, copper, zinc
Silver, tin, nickel
Silver, lead, zinc
Silver, copper, aluminium
German silver contains
1% silver
2% silver
5% silver
No silver