Galvanic corrosion cannot be prevented by
Cathodic protection
Anodic protection
Usage of largest possible anodic area
Any one of these
Correct Answer :
B. Anodic protection
Related Questions
If the demand for an item is trebled and the order cost is reduced to one third, then the economic order quantity
Is trebled
Remains unchanged
Decreases by a factor of 3
Decreases by a factor of 1/3
Wrought iron is never shaped by
Casting
Cold working
Forging
Welding
Which of the following is not categorised as the ore agglomeration process?
Nodulising
Pelletising
Balling
Briquetting
Unit of viscosity in CGS system is
Softening of hardened steel is done by its
Normalising
Tempering
Annealing
Carburising
Addition of __________ to steel does not impart hardness.
Nickel
Copper
Chromium
Silicon
Stainless steel is welded using
Oxy-acetylene flame
Oxy-hydrogen flame
Arc welding
Inert gas arc welding
What is the pH of distilled water?
0
1
7
14
Normalising does not __________ of a metal.
Improve machinability & tensile strength
Remove internal stresses
Refine the structure
Remove strains caused by cold working
The elastic strain in copper is due to the
Motion of dislocations
Stretching of atomic bonds
Breakage of atomic bonds
None of the above
Air-petrol ratio for maximum power generation in spark ignition engine is about
6 : 1
12 : 1
18 : 1
24 : 1
Production of one ton of paper in Indian paper industry consumes about __________ kWh of electricity.
300
800
1400
2000
Which of the following alloying elements is present in maximum percentage in high speed steel?
Molybdenum
Chromium
Tungsten
Vanadium
Spherical shape of mercury droplets is due to its
High viscosity
Low surface tension
High density
High surface tension
Pick out the wrong statement.
Complete unity of command exists in a line organisation
Line organisation is net suitable for expansion and growth of an industry
In line and staff organisation, line executes and staff directs
None of these
A solid aluminium ball, when quenched in a water bath maintained at 40°C, cools down from 550°C to 450°C in 20 seconds. The expected temperature of the ball after next 20 seconds may be about __________ °C.
370
340
320
300
Specific __________ is a dimensionless quantity.
Heat
Humidity
Weight
None of these
Working of linear variable differential transducer (LVDT) is based on the principle of variable
Capacitance
Resistance
Mutual inductance
None of these
Oxygen cylinders used for autogenous (cutting/welding) purposes are
Seamless & made of steel
Heat treated before use
Made by sand casting
Welded steel cylinders
Tumbling is the process of improving the __________ of the materials/parts.
Surface finish
Fatigue limit
Creep limit
Surface cleanliness
Pick out the wrong statement.
For a pressure vessel to be classified as 'thin vessel', the ratio of wall thickness to mean radius is less than 0.1
For calculating forces and efficiency of riveted joint, either rivet diameter or rivet hole diameter is used in case of pressure vessel and in structural work
Longitudinal joint is normally made butt joint to maintain the circularity of the vessel
Maximum diameter of the opening provided in a pressure vessel, which does not require any compensation is 200 mm
Temperature of hot gases flowing in a pipe is measured by a thermocouple inserted in the thermal well. The thermal well made of __________ will facilitate the most accurate measurement of the temperature.
Copper
Steel
Aluminium
Brass
The kinematic viscosity (in stoke) and the absolute/dynamic viscosity (in poise) are the same for __________ at room temperature.
Air
Water
Mercury
Alcohol
Basicity 
of the slag in Indian blast furnace is in the range of
0.7-1.0
1.1-1.4
1.5 - 1.8
2.0 - 2.5
CANDU type nuclear reactor using natural uranium as fuel is the extensively used nuclear reactor because of the fact that the
Specific fuel consumption is very low due to the use of heavy water
Fuel cost is much lower than that used in pressurised water or boiling water reactor
Heavy water is used both as coolant as well as moderator
Both 'b' & 'c'
Propulsion of rocket follows from the
Newton's second law of motion
Newton's third law of motion
Law of projectiles
Archimedes principle
The surface tension of a liquid, at critical temperature is
Indeterminate
Zero
Infinity
Same as that at any other temperature
Gas turbine normally employs a constant __________ cycle.
Pressure
Temperature
Volume
None of these
With increase in steam pressure, its specific volume decreases
Rapidly first and then slowly
Linearly
Slowly first and then rapidly
Exponentially
Referring to the periodic table of elements, it is found that with increasing atomic number. The atomic size in the same
Period increases
Period decreases
Group increases
Both 'b' & 'c'