56. The rate at change of temperature is called

A. Temperature difference
B. Temperature gradient
C. Isotherm
D. None of the above

57. The rate of infiltration normally declines rapidly during the early part of rainstorm event and reaches a constant value after several hours of rainfall. The factors responsible for this phenomenon are

I. The filling of fine soil pores with water, which reduces capillary forces
II. Moistened soil, clay particles to swell and reduce the size of pores
III. Raindrop impact breaking up with soil clumps, splashing fine particles into pores

A. I, II
B. I, III
C. II, III
D. All of the above

58. The process where the particle moves from the surface to the medium in quick, continuous, repeated cycles is called

A. Saltation
B. Suspension
C. Traction
D. Solution

59. The obscuring of one celestial body by another, particularly that of the sun or a planetary satellite

A. Elliptic
B. Ecliptic
C. Eclipse
D. None of the above

60. The river Sutlej, on which the Bhakra Dam has been built, originates from

A. A spring in Vering
B. Near Bara Lacha Pass in Lahul
C. Rakas Lake in Tibet
D. Mansarovar Lake