The pressure drop per unit length for laminar flow of fluid through a long pipe is proportional to (where, A = cross-sectional area of the pipe & D = Diameter of the pipe)
A
D
1/A
1/A2
Correct Answer :
C. 1/A
Related Questions
Coating provided on the electrodes used in the arc welding is not expected to
Add alloying elements
Prevent electrode from contamination
Stabilise the arc
Provide protective atmosphere to weld
The co-ordination number in simple cubic structure is
4
6
8
12
Elimination of brittleness resulting from welding of saw blades is done by __________ of the welded portion.
Annealing
Toughening
Work hardening
Tempering
Tumbling is the process of improving the __________ of the materials/parts.
Surface finish
Fatigue limit
Creep limit
Surface cleanliness
Which of the following is not an ore of copper?
Cryolite
Azurite
Chalcopyrite
Malachite
__________ is not a case hardening process.
Carburising
Nitriding
Cyaniding
Annealing
Pick out the wrong statement.
The X-rays cannot be deflected by electric field unlike cathode rays
The intensity of X-rays can be measured by ionisation current produced due to the ionisation of gas by X-rays
The quality of X-rays can be controlled by varying the anode-cathode voltage
Crystal structure of a material can be studied by an electron microscope
The difference in one unit of Rockwell hardness number corresponds to a difference in the depth of indentation of __________ mm.
0.001
0.01
0.002
0.02
The cooling rate required to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours is __________ BTU/hr.
100
200
1000
2000
__________ is the most important element, which controls the physical properties of steel.
Manganese
Silicon
Carbon
Vanadium
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
Which of the following metals is not subjected to electrolytic refining/purification?
Copper
Zinc
Tin
Aluminium
In chemical dehumidification of air
Both specific humidity & dry bulb temperature increases
Both specific humidity & dry bulb temperature decreases
Specific humidity decreases & dry bulb temperature increases
Specific humidity increases & dry bulb temperature decreases
The difference between gross & net calorific values of fuel is due to the
Sensible heat carried away by the flue gases
Heat carried away by the steam from the moisture content of the fuel
Heat lost by radiation
Heat carried away by steam from the combustion of hydrogen in the fuel
Which of the following has the highest modulus of elasticity (about 7 × 106 kg/cm2)?
High speed steel
Stainless steel
Tungsten carbide
Superalloys
Air standard Otto cycle is more efficient than the diesel cycle for the same
Heat addition & compression ratio
Heat addition & pressure
Compression ratio & pressure
Cylinder dimension & rpm
Alcohols are not suitable as diesel engine fuel because the cetane number of alcohols is
Very low which prevents their ignition by compression
Very high which prevents their ignition by compression
Zero
None of these
Pick out the wrong statement.
Geothermal energy is a non-conventional source of energy
Mass is converted into energy in both nuclear fission & fusion reaction
Inhalation of mercury vapour is not harmful for human beings
Inhalation of arsenic causes cancer
Runge-Kutta method is used to solve a/an
Ordinary differential equation of nth order
Simultaneous non-linear equation
Linear differential equation
None of these
Highest cutting speed is achieved by the __________ tool material.
High speed steel
Carbide
Cast alloy
Plain carbon steel
Diameter of the rivet to be provided on a 20 mm. thick boiler plate will be __________ mm.
10
20
30
40
Fire refining process is employed in case of
Tin
Copper
Zinc
Aluminium
Hydrogen can be
Used in I.C. engines as fuel
Liquefied & stored under cryogenic conditions
Produced by electrolysis of water
All (A), (B) & (C)
The most important consideration in value engineering is the
Profit maximisation
Customer satisfaction
Cost reduction
Process improvement
Hot working of lead is carried out at
75°C
373°K
150°C
Room temperature
An ideal material for making cooking vessels should have
High heat capacity
Low heat capacity
High thermal conductivity
Both (B) and (C)
Particle nature of cathode rays is proved due to the fact that they
Travel in a straight line
Get deflected by magnetic electric field
Produce fluorescence
Heat the exposed material
Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to
Achieve very high purity of aluminium (99.9%)
Keep the electrolyte in liquid condition by the generation of heat
Electrolytically dissociate alumina
Both (B) & (C)
The elastic strain in copper is due to the
Motion of dislocations
Stretching of atomic bonds
Breakage of atomic bonds
None of the above
Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m2 .k), when the insulation thickness is __________ mm.
15
25
10
30