Technical Apti Set No 2

Pick up the incorrect statement from the following. For performing compressive strength test of cement

• A Cement and standards and mortar are used in the ratio of 1:3

• B Water is added at the rate of (P/4)+ 3.0 percentage of water where P is the percentage of water for standard consistency

• C A cube mould of 10 cm x 10 cm x 10 cm is used

• D The prepared moulds are kept in a atmosphere of 50% relative humidity

The span of a Astroid is increased along both the x and y axes equally. Then the

maximum value of: z = x + y along the Astroid is?

• A. Increases

• B. Decreases

• C. Invariant

• D. The scaling of Astroid is irrelevant

If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respectively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation

• A 0.1P + 0.3Y + 0.1Z = W/Cx P

• B 0.3P + 0.1Y+ 0.012 = W/C * P

• C 0.4P + 0.2Y + 0.01Z = W/C * P

• D 0.5P + 0.3Y + 0.012 = W/Cx P

Which of the following is a type of Iterative method of solving non-linear equations?

• A. Graphical method

• B. Interpolation method

• C. Trial and Error methods

• D. Direct Analytical methods

Shrinkage of concrete depends upon

(1) Humidity of atmosphere

(i) Passage of time

(iii) Stress

The correct answer is

• A (1) and (ii)

• B (ii) and (iii)

• C Only (iii)

• D All (i), (ii) and (iii)

What is the degree of the differential equation, 4x²-6x2 y²+2y=0?

• A. 3

• B. 5

• C. 1

• D. 8

For an ordinary Portland cement

• A Residual does not exceed 10% when sieved through IS Sieve No. 9

• B Soundness varies from 5 to 10 mm

• C Initial setting time is not less than 30 minutes

• D Compressive stress after 7 days, is not less than 175 kg/cm2

Which of the following is not an example of linear differential equation?

• A. y=mx+c

• B. x+x=0

• C. x+x²=0

• D. x"+2x=0

Joints in concrete structures, are provided

• A To reduce the tensile stresses likely to be developed due to evaporation of water

• B To minimize the change in the dimensions of the slab

• C To minimize the necessary cracking

• D All the above

The weight of one cubic metre of R.C.C is

• A. 1400kg

• B. 1800kg

• C. 2100kg

• D. 2400kg