During uniaxial compressive testing of a rock specimen of diameter 54 mm and length 120 mm, the axial strain was found to be 6.5 × 10-4 mm/mm. If the Poisson's ratio of the rock is 0.3, the volumetric strain of the rock specimen in mm/mm is

A rock specimen of 120 mm length and 54 mm diameter is subjected to uniaxial compressive loading. Two strain gauges, one axially and other radially, are attached to the specimen. At the breaking load, if these two gauges read 0.0082 m/m and 0.0023 m/m respectively, the Poisson's ratio of the specimen is

A

3.56

B

0.25

C

0.28

D

0.32

The ratio of uniaxial compressive strength to uniaxial tensile strength of a sandstone specimen is 8 : 1. The theoretical, value of angle of internal friction of the specimen in degree is

A

51

B

41

C

32

D

7

From an alloy, two specimens are machined and tested separately under tension and compression. The engineering stress-strain curves as well as the true stress-true strain curves for tension and compression are plotted in the same diagram. Identify the correct statements:
P. The engineering stress-strain curves in tension and compression are identical.
Q. The true stress-true strain curve in compression is lower than the true stresstrue strain curve in tension due to Bauschinger effect.
R. The true stress-true strain curve in tension is above the corresponding engineering stress-strain, curve.
S. The true stress-true strain curve in tension and compression are identical.

A

P, Q

B

Q, R

C

Q, S

D

R, S

The rock specimen obtained from the overlying strata in a coal mine were tested in uni-axial compression and the following results were obtained at 50% of average compressive strength
Longitudinal strain = 0.06 and Lateral strain = 0.012
The ratio of vertical to horizontal stress in the mine is

A

3.0

B

4.0

C

2.5

D

0.3

When an open coiled helical compression spring is subjected to an axial compressive load, the maximum shear stress induced in the wire is (where D = Mean diameter of the spring coil, d = Diameter of the spring wire, K = Wahl's stress factor and W = Axial compressive load on the spring)

A

$$\frac{{{\text{WD}}}}{{\pi {{\text{d}}^3}}} \times {\text{K}}$$

B

$$\frac{{2{\text{WD}}}}{{\pi {{\text{d}}^3}}} \times {\text{K}}$$

C

$$\frac{{4{\text{WD}}}}{{\pi {{\text{d}}^3}}} \times {\text{K}}$$

D

$$\frac{{8{\text{WD}}}}{{\pi {{\text{d}}^3}}} \times {\text{K}}$$

A core sample of 54 mm diameter having Young's modulus of 68.97 Gpa fails in uniaxial compression at 0.1% axial strain. The axial load at failure in kN is

A

158.00

B

68.97

C

58.00

D

15.80

The uniaxial compressive strength of a limestone sample is 80 MPa. The sample is confined at a pressure of 20 MPa in a triaxial compressive strength test. Based on Hoek-Brown failure criteria the maximum principal stress at failure in MPa is
(Consider rock constants as m = 7.88, s = 1.0 and a = 0.5)

A

117.9

B

132.3

C

137.9

D

157.9

In a point load test on 50 mm diameter core specimen. rupture was observed at a load of 5000 kg. The uni-axial compressive strength of the specimen was

A

3800 kg/cm2

B

4000 kg/cm2

C

4800 kg/cm2

D

5000 kg/cm2

Rock mass parameters for a shale rock, m_b, s, and a of the Hoek and Brown failure criterion as given in the equation are 2.4, 0.01 and 0.52 respectively. The uni-axial compressive strength (σ_Ci) of intact sh!le is 50 MPa.
$${\sigma _1} = {\sigma _3} + {\sigma _{ci}}{\left( {{m_b}\frac{{{\sigma _3}}}{{{\sigma _{ci}}}} + S} \right)^a}$$
The global rock mass strength of shale in MPa is

A

1.2

B

10.29

C

20.83

D

50,00

The following characteristic curves (P, Q, R, S) pertain to rotary drilling in rock.

Title of the curve
I : Torque versus RPM
II: Rate of penetration versus uniaxial compressive strength of rock
III : Rate of penetration versus weight on bit
IV : Specific energy versus weight on bit
Match the curves with their titles

A

P-III, Q-IV, R-II, S-I

B

P-II, Q-IV, R-I, S-III

C

P-IV, Q-III. R-II, S-I

D

P-I, Q-III, R-II, S-IV