In the torsion equation T/J = τ/r = Gθ/ L, the term J/R is called
Shear modulus
Section modulus
Polar modulus
None of these
Correct Answer :
C. Polar modulus
Related Questions
In order to prevent crushing of masonry at the base of the dam, the maximum stress should be __________ the permissible stress of the soil.
Equal to
Less than
More than
None of these
One Joule (J) is equal to
1 N-m
1 kN-m
10 N-m/s
10 kN-m/s
Producer gas is obtained by
Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
Carbonisation of bituminous coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 650°C
During which of the following process does heat rejection takes place in Carnot cycle?
Isothermal expansion
Isentropic expansion
Isothermal compression
Isentropic compression
Which of the following is a proper sequence?
Proportional limit, elastic limit, yielding, failure
Elastic limit, proportional limit, yielding, failure
Yielding, proportional limit, elastic limit, failure
None of the above
For a perfect gas, according to Boyle's law (where p = Absolute pressure, v = Volume, and T = Absolute temperature)
p v = constant, if T is kept constant
v/T = constant, if p is kept constant
p/T = constant, if v is kept constant
T/p = constant, if v is kept constant
The fuel mostly used in steam boilers is
Brown coal
Peat
Coking bituminous coal
Non-coking bituminous coal
Modulus of rigidity is defined as the ratio of
Longitudinal stress to longitudinal strain
Volumetric stress to volumetric strain
Lateral stress to Lateral strain
Shear stress to shear strain
The rivets are used for __________ fastenings.
Permanent
Temporary
Semi-permanent
None of these
One kg of carbon monoxide requires _______kg of oxygen to produce 11/7 kg of carbon dioxide gas.
11/7
9/7
4/7
All of the above
In an irreversible process, there is a
Loss of heat
No loss of heat
Gain of heat
No gain of heat
The ultimate tensile stress of mild steel compared to ultimate compressive stress is
Same
More
Less
Unpredictable
According to Regnault's law, the specific heat at constant pressure (cp) and specific heat at constant volume (cv) _________ with the change in pressure and temperature of the gas.
Change
Do not change
Both (A) and (B)
None of these
The heat and mechanical energies are mutually convertible. This statement was established by
Boyle
Charles
Joule
None of these
A process, in which the working substance neither receives nor gives out heat to its surroundings during its expansion or compression, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process
The atomic mass of oxygen is
12
14
16
32
For a beam, as shown in the below figure, the deflection at C is (where E = Young's modulus for the beam material, and I = Moment of inertia of the beam section.
Wl3/48 EI
Wa²b²/3EIl
[Wa/(a√3) x EIl] x (l² - a²)3/2
5Wl3/384 EI
In the torsion equation T/J = τ/r = Gθ/ L, the term J/R is called
Shear modulus
Section modulus
Polar modulus
None of these
If the value of n = 0 in the equation pvn = C, then the process is called
Constant volume process
Adiabatic process
Constant pressure process
Isothermal process
The general law of expansion or compression is pvn = C, The process is said to be hyperbolic, if n is equal to
0
1
γ
∝
The given figure shows the Mohr's circle of stress for two unequal and like principal stresses (σx and σy) acting at a body across two mutually perpendicular planes. The normal stress on an oblique section making an angle θ with the minor principle plane is given by
OC
OP
OQ
PQ
The buckling load for a given material depends on
Slenderness ratio and area of cross-section
Poisson's ratio and modulus of elasticity
Slenderness ratio and modulus of elasticity
Slenderness ratio, area of cross-section and modulus of elasticity
The work ratio of simple gas turbine cycle depends upon
Maximum cycle temperature
Minimum cycle temperature
Pressure ratio
All of these
The efficiency of Carnot cycle is maximum for
Gas engine
Petrol engine
Steam engine
Reversible engine
In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be
Increase key length
Increase key depth
Increase key width
Double all the dimensions
An open system is one in which
Heat and work crosses the boundary of the system, but the mass of the working substance does not crosses the boundary of the system
Mass of the working substance crosses the boundary of the system but the heat and work does not crosses the boundary of the system
Both the heat and work as well as mass of the working substance crosses the boundary of the system
Neither the heat and work nor the mass of the working substance crosses the boundary of the system
The hyperbolic process is governed by
Boyle's law
Charles' law
Gay-Lussac law
Avogadro's law
If in the equation pvn = C, the value of n = ∝, then the process is called
Constant volume process
Adiabatic process
Constant pressure process
Isothermal process
The state of stress at a point in a loaded member is shown in the below figure. The magnitude of maximum shear stress is
10 MPa
30 MPa
50 MPa
100 MPa
The efficiency of Diesel cycle with decrease in cut-off
Increases
Decreases
First increases and then decreases
First decreases and then increases