The concentration of (H+) ions is 4 x 10-5 in a solution. Then pH of the solution will be (Given log 4 = 0.6)
4.4
5.6
8.4
2.4
Correct Answer :
A. 4.4
Related Questions
Which of the following is a commonly used manometric liquid for low pressure range?
Ethyl alcohol
Carbon tetrachloride
Glycerol
Ethylene glycol
The malleability of a material is the property by virtue of which it can be rolled or hammered into thin sheets. Which of the following materials has the maximum malleability?
Lead
Copper
Aluminium
Wrought iron
Air-petrol ratio for maximum power generation in spark ignition engine is about
6 : 1
12 : 1
18 : 1
24 : 1
Temperature attained in soldering of metals is about __________ °C.
150-300
400-500
650-800
1000-1100
Heat flow across a hollow sphere of inner radius 'r1' and outer radius 'r2' is directly proportional to
(r2 - r1)/r1. r2
r1. r2/(r2 - r1)
(r2 + r1)/r1. r2
r1. r2/(r2 + r1)
Heat transfer by __________ is almost absent in case of fluidised bed drying operation.
Radiation
Conduction
Convection
Both (B) & (C)
For efficient performance of a blast furnace, the extent of reduction of Wustite (FeO) should be
100% indirect reduction
100% direct reduction
50-60% indirect reduction
30-40% indirect reduction
Austempering of steel requires it to be heated to 875°C followed by sudden cooling to 250-525°C, thereby changing austenite to
Sorbite
Bainite
Martensite
Troostite
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
The laminar boundary layer thickness in zero pressure gradient flow over a flat plate along the x-direction varies as x0.5 while the thickness of turbulent boundary layer varies as (where, x = distance from the leading edge)
x1.5
x0.8
x-1.5
x-0.8
Joining of thin foils is preferred to be done by
Gamma rays
X-rays
Microwaves
Gas welding
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'
Tip of the match stick contains a mixture of
K + S
K + S + K2Cr2O7
S + K2Cr2O7 + White P
None of these
The delivery pressure of boiler feed water pump compared to the boiler steam pressure is
Same
Slightly less
Slightly more
Much more
Super conduction in metals is observed at a temperature of __________ °K.
<100
>100
About 273
About 373
Pick out the wrong statement.
A soft magnetic material should have high permeability and small area of hysteresis loop
Poisson's ratio of high melting point metals is more than unity
Solders generally melt at less than 185°C
Steel produced by B.O.F process is ideally suited for manufacturing flat product
__________ is not used as a material of construction in thermocouples.
Alumel
Rhodium
Constantan
Duralumin
A solar cell converts the sunlight directly into __________ energy.
Thermal
Electrical
Mechanical
Chemical
Materials having resistivity ranging from 1 to 100 ohm. cm is termed as
Conductor
Insulator
Semi-conductor
None of these
Identify the correct statement with reference to the extractive metallurgy of aluminium.
The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3
Approximately 80% of the aluminium deposited on the cathode comes from cryolite
Sodium is deposited along with aluminium, but is immediately vaporised
Anode effect sets in when the cryolite concentration goes below 40%.
Fahrenheit and Centigrade scales have the same readings at
-55°
-40°
-33°
-58°
Thermal diffusivity of a substance is proportional to (where, k = Thermal conductivity)
1/k
k
k2
1/k2
The normal stress is the same in all directions at a point in a fluid, only when the fluid
Is at rest & has zero viscosity
Is frictionless
Fluid layer has no motion relative to an adjacent layer of fluid
is incompressible & frictionless
In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is
1
1.4
1.5
Y = Cp/Cv
Which of the following phenomenon/ phenomena is/are diffusion controlled?
Dislocation climb
Cross-slip
Twinning
Recrystallisation
The most suitable material of construction for a sewer to carry sewage under high pressure is
Asbestos cement
Steel
Cement concrete
Stoneware
The value of 
for air & most common gases can be safely assumed to be
0.8
1
1.4
1.8
The mechanism which changes the value of manipulated variable in response to the output signal from the control unit is called the
Final control element
On-off control
Floating control action
None of these
Out of the following __________ iron has the best capability to bear sudden & excessive shocks.
White
Cast
Wrought
Pig
An example of unsteady non uniform flow is the flow of liquid under pressure through a
Tapering pipe at constant flow rate
Tapering pipe at either decreasing or increasing flow rate
Long pipeline of constant diameter
None of these