SUNDAY WEEKLY EXAM (15/06/2025)

Which of the following statements is correct regarding the degree of static indeterminacy (Ds) of a plane frame?

• Ds = 3m - 3j + R
• Ds = m - 2j + R
• Ds = 3m - j + R
• Ds = m - j + R

Answer explanation

For a plane frame: Ds = 3m - 3j + R, where m = members, j = joints, R = reactions.

In Kennedy's theory of canal design, the critical velocity is a function of:

• Hydraulic radius
• width of channel

• Mean velocity and depth
• Channel slope only

Answer explanation

Kennedy proposed Vc = 0.55 mD^0.64; depends on mean velocity and depth.

Creep in rails is primarily caused by:

• Temperature variations
• Loose fastenings
• Action of braking and acceleration
• Misalignment of joints

Answer explanation

Creep is primarily caused by traction and braking forces which induce longitudinal forces.

Which IS code is followed for the design of unlined canals?

• IS 3370
• IS 456
• IS 7112
• IS 800

Answer explanation

IS 7112 is the Indian Standard Code for Design of Lined Canals.

The unit hydrograph of a basin is based on which of the following assumptions?

• Non-linearity of runoff
• Time invariance of runoff
• Rainfall and runoff are linearly related
• Runoff depends on prior rainfall

Answer explanation

Unit hydrograph theory assumes linear relationship between rainfall excess and runoff.

Assertion (A): Railway sleepers are placed perpendicular to the rails. Reason (R): Sleepers help in maintaining gauge and transferring loads.

• Both A and R are true, and R is the correct explanation of A
• Both A and R are true, but R is not the correct explanation of A
• A is true, R is false
• A is false, R is true

Answer explanation

Sleepers maintain the track gauge and transfer loads, thus placed perpendicular to rails.

Statement 1: A higher section modulus increases the bending resistance of a beam. Statement 2: Section modulus depends on the geometry of cross-section.

• Both statements are true
• Statement 1 is true, Statement 2 is false
• Statement 1 is false, Statement 2 is true
• Both statements are false

Answer explanation

Higher section modulus gives higher bending resistance; it depends on geometry.

Which method is used for plotting contour lines from spot levels taken over a grid?

• Cross-section method
• Direct method
• Graphical method
• Grid method

Answer explanation

Grid method uses square grid with interpolated contours using spot levels.

If a beam of rectangular section is subjected to shear force, the shear stress distribution is:

• Triangular
• Parabolic
• Uniform
• Rectangular

Answer explanation

Shear stress in a rectangular beam is parabolic with max at neutral axis.

Which of the following instruments is used in hydrographic surveying?

• Echo sounder
• Planimeter
• Alidade
• Barometer

Answer explanation

Echo sounder is used to determine depth of water in hydrographic surveying.