72. If the water table rises upto ground surface, then the___________________?

A. effective stress is reduced due to decrease in total stress only but pore water pressure does not change
B. effective stress is reduced due to increase in pore water pressure only but total stress does not change
C. total stress is reduced due to increase in pore water pressure only but effec-tive stress does not change
D. total stress is increased due to de-crease in pore water pressure but effective stress does not change
✅ The correct answer is option B.

73. A retaining wall 6m high supports a backfill with a surcharge angle of 10°. The back of the wall is inclined to the vertical at a positive batter angle of 5°. If the angle of wall friction is 7°, then the resultant active earth pressure will act at a distance of 2 m above the base and inclined to the horizontal at an angle of_________________?

A. 7°
B. 10°
C. 12°
D. 17°
✅ The correct answer is option C.

77. In a deposit of normally consolidated clay_________________?

A. effective stress increases with depth but water content of soil and un-drained strength decrease with depth
B. effective stress and water content increase with depth but undrained strength decreases with depth
C. effective stress and undrained strength increase with depth but water content decreases with depth
D. effective stress, water content and undrained strength decrease with depth
✅ The correct answer is option C.