Know your strengths and practice your concepts with this quiz on NHPC JE Recruitment 2021. This quiz for NHPC JE Recruitment 2021 is designed specially according to NHPC Syllabus 2021.
Quiz: Civil Engineering
Each question carries 1 mark
Negative marking: 1/4 mark
Time: 8 Minutes
Q1. In a closed helical spring subjected to an axial load, other quantities remaining the same, if the wire diameter is doubled and mean radius of the wire diameter is doubled and mean radius of the coil is also doubled, then stiffness of spring when compared to original one will become________.
(b) Four times
(c) Eight times
(d) Sixteen times
Q2. The volume (in milliliters) occupied by aerated mixed liquor containing one gram of dry solids after setting for 30 minutes is termed as:
(a) Allowable solids content
(b) Sludge volume index
(c) Liquor index
(d) Chlorination limit
Q3. What will be the shift of transition curve, if the length of transition curve is 80 m. and radius of the curve is 320 m?
Q4. Oleic acid may be used in the manufacture of:
(a) White cement
(b) Hydrophobic cement
(c) Anti-bacterial cement
(d) Portland pozzolana cement
Q5. A soil sample has bulk density of 21 kN/m^3 and water content 8%. Dry density of the sample is:
(a) 19.00 kN/m^3
(b) 18.44 kN/m^3
(c) 22.68 kN/m^3
(d) 19.44 kN/m^3
Q6. In a tension splice the number of rivets carrying calculated shear stress through a packing greater than 6mm thick, is to be increased by 2.5% for each _________ thickness of packing.
(a) 1 mm
(b) 1.5 mm
(c) 2 mm
(d) 2.5 mm
Sol. Spring stiffness, K=(Gd^4)/(8D^3 N)
K^’=(G×2^4.d^4)/(8×2^3×D^3 N)=2[(Gd^4)/(8D^3 N)]
Sol. Sludge volume index → Sludge volume index is defined as volume occupied in ml. by 1 gm. Of solid in the mix liquor when allow to settle for 30 min.
▭(SVI=(Settled Sludge volume (ml))/(MLSS(gm.)))
Length of transition curve (L_s) = 80 m
Radius of the curve (R) = 320 m
Shift(s) = (L_s^2)/24R
= 0.83 m
Sol. Hydrophobic cement → A film of stearic acid and oleic acid is formed which reduces the rate of deterioration of cement during long storage.
Sol. In tension splice the number of rivets carrying shear stress through a packing greater than 6 mm thick is to be increased by 2.5% for each 2 mm thickness of packing.