Quiz: Civil Engineering

Exam: SSC-JE

Topic: MISCELLANEOUS

Each question carries 1 mark

Negative marking: 1/4 mark

Time: 10 Minutes

Q1. The total mass of a 1.2 cum volume of soil is 2.4 MT. if this soil is at a moisture content of 25%, then the dry density (kg/cum) of this soil will be:

(a) 1200

(b) 1920

(c) 1600

(d) 1560

Q2. If a soil sample of weight 0.18 kg having a volume of 0.0001 m³ and dry unit weight of 1600 kg/m³ is mixed with 0.02 kg of water then the water content in the sample will be

(a) 30%

(b) 25%

(c) 20%

(d) 15%

Q3. If the undisturbed strength of a soil sample is 50 units while the remolded strength is 20 units, then what is the sensitivity of this soil?

(a) 1.25

(b) 0.4

(c) 2.5

(d) 2

Q4. Clay whose activity coefficient is more than 1.2 is termed as______.

(a) fine clay

(b) inactive clay

(c) active clay

(d) normal clay

Q5. Direct method of contouring is-

(a) A quick method

(b) Adopted for large surveys only

(c) Most accurate method

(d) Suitable for hilly terrains

Q6. Critical flow is created at a section of a rectangular channel 2.5 m wide. If the discharge is 2 m³/s what would be the critical flow depth?

(a) 0.62 m.

(b) 0.54 m.

(c) 0.48 m.

(d) 0.40 m.

Q7. A laser – doppler anemometer is a device to measure

(a) shear stress at a boundary

(b) surface tension of a fluid

(c) the turbulent velocity fluctuation in a flow

(d) drag force on an aerofoil

Q8. 8 m³/s discharge flows through 4 wide rectangular channel at a velocity of 2 m/s. The hydraulic mean radius of the channel is:

(a) 3/2m

(b) 2/3m

(c) 1m

(d) 4m

Q9. If the Euler load for a column is 1000 kN and crushing load is 1200 kN, then the Rankine load will approximately be:

(a) 1200

(b) 600

(c) 900

(d) 545

Q10. When both ends of a column are fixed, the crippling load is F. if one end of the column is made free, the value of crippling load will be changed to………..

(a) F/4

(b) F/2

(c) f/16

(d) 4F

SOLUTION

S1. Ans.(c)

Sol. Mass of soil = 2.4 MT = 2.4 ×10³ kg

Volume of soil = 1.2 m³

Density of soil = (2.4×10^3)/1.2=2×10^3 kg\/m^3

Moisture content = 25%

Dry density (r_d )=r_b/(1+w)

=(2×10^3)/(1+0.25)

=1600 kg\/m^3

S2. Ans.(b)

Sol. weight of soil = 0.18 kg.

Volume of soil = 0.0001 m³

Dry unit weight = 1000 kg/m³

r_d=Weight/volume

1600=W/0.0001

weight of solid = 0.16 kg.

Weight of water = 0.18 – 0.16

= 0.02 kg.

Total weight of water = 0.02 + 0.02

= 0.04 kg.

Water content (w) = 0.04/0.16×100

▭(W=25%)

S3. Ans.(c)

Sol. Sensitivity=(undisturbed strength)/(remalded strength)

St=50/20

▭(St=2.5 )

S4. Ans.(c)

Sol.

Activity Disruption

< 0.75

0.75 to 1.25

> 1.25 Non active

Normal soil

Active

S5. Ans.(c)

Sol. direct method of contouring is the most accurate method. It’s suitable for large scale map’s when ground surface is regular.

S6. Ans.(d)

Sol. In critical flow

Froud No. (fr) = 1

v/√gy = 1

Q/(A√gy) = 1

2/(2.5×y √gy) = 1

2/(2.5×y √(9.81×y)) = 1

2 = 2.5 × y × √(9.81×y)

y = 0.40 m

S7. Ans.(c)

Sol. Turbulent velocity fluctuation in a flow is measured by lases doppler anemometer.

S8. Ans. (b)

Sol. discharge (Q) = 8 m³/sec

width (B) = 4

Velocity (V) = 2 m/sec

Hydraulic mean Radious (R) = ?

R = A/P

A → Area

P → Perimeter

Q = AV

8 = A × 2

A = 4

B × Y = 4

4 × y = 4

y = 1

Perimeter (P) = B + 2Y

= 4 + 2 × 1

= 6 m

R = 4/6

R = 2/3

S9. Ans.(d)

Sol. Pe= 1000 KN

Pcr = 1200 KN

Rankine load = ?

1/P=1/Pe+1/Pc

1/P=1/1000+1/1200

P= 545.45 KN

S10. Ans.(c)

Sol.

Le=L/2

F= (π^2 EI×4)/L² -(1)

(ii)

Le= 2L

Pcr = π²EI/4L² From equation(1)

Pcr = F/16