DRDO STA Computer Science Civil Tier 2 Mock Test- 1 Free Online Test 2026

(1) Opening each up to 1000sq cm 0.1 square meter

(2) Ends of beams, post, rafters, etc. up to 500 sq.cm or 0.05 sq.m in section.

(3) Bed plate, wall plate, bearing of balcony (chajja) and the like up to 10 cm depth. Bearing of floor and roof slabs are not deducted from masonry.

The final deflection due to all loads i.e the effect of temperature, creep and shrinkage as measured from the cast level of the support shall not be greater than span/250.

Initially, when supply increases plants will get adequate water depth for their growth but ager certain limit water will cause water logging thus, degrading the growth of plants.

Basic values of span to effective depth ratios for spans up to 10 m:

• Cantilever 7

• Simply supported 20

• Continuous 26

For spans above 10 m, the values in (a) may be multiplied by lo/span in metres, except for cantilever in which case deflection calculations should be made.

LSF = Percentage of lime/Percentage of alumina + iron oxide + silica

It generally lies between 0.66 to 1.02.

Rich: 1 part cement, 2 parts sand, 3 parts coarse aggregate. A rich mix is used for concrete roads and waterproof structures.

Standard: 1 part cement, 2 parts sand, 4 parts coarse aggregate. A standard mix is used for reinforced work floors, roofs, columns, arches, sewers, tanks etc.

Medium: 1 part cement, 2 1/2 parts sand, 5 parts coarse aggregate. A medium mix is used for foundations, walls, abutments, piers, etc. For a medium strength concrete the water-cement ration should not be less than 0.4. 

Lean: 1 part cement, 3 parts sand, 6 parts coarse aggregate. A lean mix is used for all mass concrete work, large foundations, backing for stone masonry, etc.

The percentage of Earth covered by oceans is approximately:

• The oceans cover about 71% of the Earth's surface.

• This extensive coverage plays a crucial role in regulating climate and supporting diverse ecosystems.

• Oceans are vital for marine life, providing habitat and resources.

• They also influence weather patterns and are essential for human activities such as fishing and transportation.

The area Ratio should be less than 10%.

Inside Clearance should be between 0.5 to 3.

Outside Clearance should be between 0 to 2.

The cutting,, edge angle should be within 20°.

Phytometer is used to measure transpiration.

The percentage of total quantity of fresh water in the world available in the liquid form is about 3%.

The vast majority of the Earth's water is in the form of oceans, which are saltwater and not suitable for drinking or irrigation. Freshwater, which is water that is free of salt and other minerals and is suitable for drinking and irrigation, makes up a very small percentage of the Earth's total water supply. According to the United Nations, about 2.5% of the Earth's water is freshwater, and of that, only about 0.3% is available as surface water in lakes, rivers, and streams, while about 2.2% is found in groundwater reserves. In other words, about 3% of the total quantity of water on Earth is available in the liquid form as freshwater.

∴ l = unsupported length of column and d = lateral dimension of the column

In the case of uniaxial stress, maximum principal stress σ1 and minimum principal stress σ2 will be PA and zero, respectively.

Maximum shear stress (\tau)

Plane of maximum shear stress,

tan⁡2θ=∞,⇒θ=45^∘

∴ The maximum shear stress and its inclination with the direction of load, respectively, are P/2A and 45°.

i) Wayside stations: In this type of station, an arrangement is made to cross an up and a down train or for overtaking of the slower trains by the faster trains.

ii) Junctions: In this type of stations, the branch line meets the main line and hence the arrangements are made:

• To facilitate the interchange of traffic between main and branch lines

• To clean and repair the vehicle of the trains which terminates at the junctions

iii) Terminals: The station at which a railway line or one if its branch ends is known as a terminal station or terminal junction.

Catch sidings are provided in case of a hilly area where steep gradients occur near the station. The purpose of catch sidings is to arrest the vehicles which have started running back on the line.

1. reduce the water – cement ratio thus to improve the workability of concrete.

2. To delay the setting time of cement.

Note: Admixtures has no direct affect on the strength of concrete

Let’s analyze the soil symbols and their characteristics:

• ML (A): This is Inorganic silt with small compressibility, so it matches with 3 from List-II.
• SM (B): This refers to Silty sand, which is typically soil with small compressibility, so it matches with 1 from List-II.
• Pt (C): This refers to Soil with high organic content with high compressibility, so it matches with 4 from List-II.
• MH (D): This refers to Inorganic silt with large compressibility, so it matches with 2 from List-II.

Thus, the correct answer is C: C.

K_D = 0.5 × .434 = 0.217

Now BOD in 5 days,

(BOD)₅ = (BOD)₀ (1 – 10^-KD^t)

= 200 (1 – 10^-5×.217)

= 183.55

Hence, BOD consumed = 200 – 183.55 = 16.45

• Sherardizing (Zinc coating)

• Calorizing (Aluminium coating)

• Chromizing (Chromium coating)

Anodizing: Anodizing is to provide a decorative and corrosion-resistant coating on aluminium and its alloys only.

A thin coating of oxide on aluminium can protect the surface from corrosion.

Aluminium is ideally suited to anodizing, although other non-ferrous metals such as magnesium and titanium also can be anodized.

Parkerising is a process used for making thin phosphate coating on steel.

Galvanizing: It is a process of giving a protective coating of zinc on iron sheets and components to protect the surface from corrosion. It is the process of coating of zinc by hot- dipping.

Lake evaporation = Pan Coefficient (C_p) × Pan Evaporation

600 × 1 + R_D × 3 – 600 × 4 = 0

∴ R_D = 1000 N

For Force equilibrium equation, ∑F_y = 0

R_C = R_D = 1000 N

1. increases the rate of gain of compressive strength of concrete

2. Reduces the shear strength of concrete

3. Increases the speed of chemical reaction

When the concrete is in contact with or buried under aggressive subsoil/groundwater, this condition is considered very severe.

Measurement of Turbidity: -

A. Based on the absorption principles

1. Turbidity Rod

2. Jackson’s Turbidity meter

3. Baylis Turbidimeter

B. Based on the scattering principle

1. Modern Nephelometer

Through Nessler’s tubes on Burgess scale, true colour is measured.

Spectrophotometry is the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.

The titrimetric analysis consists of determining the number of moles of reagent (titrant), required to react quantitatively with the substance being determined.

Firstly, metals are coated with primers, and then oil or other paints are applied. But if there is a presence of moisture while applying primer, the life of oil paints is affected badly as there won’t be complete bonding between the surface and the paint.

effective length, l_o = 0.7 × 5000 = 3500 mm

for isolated ‘T’ beam, effective flange width, 
 

where, b = 1500 mm

b_w = width of the web = 450 mm
  + 450 = 1002.63mm