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4

When a body is subjected to biaxial stress i.e. direct stresses (σx) and (σy) in two mutually perpendicular planes accompanied by a simple shear stress (τxy), then minimum normal stress is

A. x + σy)/2 + (1/2) × √[(σx - σy)² + 4 τ²xy]

B. x + σy)/2 - (1/2) × √[(σx - σy)² + 4 τ²xy]

C. x - σy)/2 + (1/2) × √[(σx + σy)² + 4 τ²xy]

D. x - σy)/2 - (1/2) × √[(σx + σy)² + 4 τ²xy]

Correct Answer :

B. (σx + σy)/2 - (1/2) × √[(σx - σy)² + 4 τ²xy]


Related Questions

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Those substances which have so far not been resolved by any means into other substances of simpler form are called

A. Elements

B. Compounds

C. Atoms

D. Molecules

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Brayton cycle consists' of following four processes

A. Two isothermals and two isentropic

B. Two isentropic and two constant volumes

C. Two isentropic, one constant volume and one constant pressure

D. Two isentropic and two constant pressures

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4

Kelvin-Planck's law deals with

A. Conservation of work

B. Conservation of heat

C. Conversion of heat into work

D. Conversion of work into heat

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A composite bar made up of steel and copper bars of equal lengths are heated through 100°C. The stresses developed shall be

A. Tensile in both the material

B. Tensile in steel and compressive in copper

C. Compressive in steel and tensile in copper

D. Compressive in both the materials

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4

Which of the following is the correct statement?

A. For a given compression ratio, both Otto and Diesel cycles have the same efficiency.

B. For a given compression ratio, Otto cycle is more efficient than Diesel cycle.

C. For a given compression ratio, Diesel cycle is more efficient than Otto cycle.

D. The efficiency of Otto or Diesel cycle has nothing to do with compression ratio.

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4

The calorific value of gaseous fuel is expressed in

A. kJ

B. kJ/kg

C. kJ/m2

D. kJ/m3

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4

When a body is subjected to a direct tensile stress (σx) in one plane accompanied by a simple shear stress (τxy), the maximum normal stress i

A. (σx/2) + (1/2) × √(σx² + 4 τ²xy)

B. (σx/2) - (1/2) × √(σx² + 4 τ²xy)

C. (σx/2) + (1/2) × √(σx² - 4 τ²xy)

D. (1/2) × √(σx² + 4 τ²xy)

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4

Which of the following cycles has maximum efficiency?

A. Rankine

B. Stirling

C. Carnot

D. Brayton

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4

The __________ is obtained when carbonisation of coal is carried out at 500° to 700° C.

A. Soft coal

B. Hard coal

C. Pulverised coal

D. Bituminous coal

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The rivets are used for __________ fastenings.

A. Permanent

B. Temporary

C. Semi-permanent

D. None of these

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A molecule consisting of one atom is known as

A. Mono-atomic

B. Di-atomic

C. Tri-atomic

D. Poly-atomic

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4

The efficiency of the Carnot cycle is (where T1 and T2 = Highest and lowest temperature during the cycle)

A. (T1/T2) - 1

B. 1 - (T1/T2)

C. 1 - (T2/T1)

D. 1 + (T2/T1)

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The total strain energy stored in a body is termed a

A. Resilience

B. Proof resilience

C. Modulus of resilience

D. Toughness

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The __________ states that change of internal energy of a perfect gas is directly proportional to the change of temperature.

A. Boyle's law

B. Charle's law

C. Gay-Lussac law

D. Joule's law

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4

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.

A. Wl3/48 EI

B. Wa²b²/3EIl

C. [Wa/(a√3) x EIl] x (l² - a²)3/2

D. 5Wl3/384 EI

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4

The principal constituents of a fuel are

A. Carbon and hydrogen

B. Oxygen and hydrogen

C. Sulphur and oxygen

D. Sulphur and hydrogen

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The bending equation is

A. M/I = σ/y = E/R

B. T/J = τ/R = Cθ/l

C. M/R = T/J = Cθ/l

D. T/l= τ/J = R/Cθ

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If in the equation pvn = C, the value of n = ∝, then the process is called

A. Constant volume process

B. Adiabatic process

C. Constant pressure process

D. Isothermal process

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The condition for the reversibility of a cycle is

A. The pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process

B. All the processes, taking place in the cycle of operation, must be extremely slow

C. The working parts of the engine must be friction free

D. All of the above

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The temperature at which the volume of a gas becomes zero is called

A. Absolute scale of temperature

B. Absolute zero temperature

C. Absolute temperature

D. None of these

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Which of the following is the extensive property of a thermodynamic system?

A. Pressure

B. Volume

C. Temperature

D. Density

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The general law of expansion or compression is pvn = C, The process is said to be hyperbolic, if n is equal to

A. 0

B. 1

C. γ

D.

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Strain energy is the

A. Energy stored in a body when strained within elastic limits

B. Energy stored in a body when strained up to the breaking of a specimen

C. Maximum strain energy which can be stored in a body

D. Proof resilience per unit volume of a material

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Which of the following gas has a minimum molecular mass?

A. Oxygen

B. Nitrogen

C. Hydrogen

D. Methane

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The value of one bar (in S. I. units) is equal to

A. 1 × 102 N/m2

B. 1 × 103 N/m2

C. 1 × 104 N/m2

D. 1 × 105 N/m2

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In an extensive property of a thermodynamic system

A. Extensive heat is transferred

B. Extensive work is done

C. Extensive energy is utilised

D. None of these

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Shear modulus is the ratio of

A. Linear stress to linear strain

B. Linear stress to lateral strain

C. Volumetric strain to linear strain

D. Shear stress to shear strain

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In a prismatic member made of two materials so joined that they deform equally under axial stress, the unit stresses in two materials are

A. Equal

B. Proportional to their respective moduli of elasticity

C. Inversely proportional to their moduli of elasticity

D. Average of the sum of moduli of elasticity

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The oxygen atom is ________ times heavier than the hydrogen atom.

A. 2

B. 8

C. 16

D. 32

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Which of the following is a reversible non-flow process?

A. Isochoric process

B. Isobaric process

C. Hyperbolic process

D. All of these