GATE 2022 Rapid Revision Quiz 7

Which of the following is not correct in connection with canal lining?

The concentration of Na, Ca and Mg are 21, 3 and 1.5 meq respectively and the electrical conductivity is 200 micro mho/cm at 25◦C .

Which one of the following statements is true?

i. Correction due to earth’s curvature is always negative

ii. Correction due to refraction is always negative

iii. Combined correction due to curvature and refraction is always negative

A closed traverse has the following lengths and bearings:

The length CD and bearing AB couldn’t be measured due to some obstruction to chaining and local attraction. What are the exact length of CD and bearing of AB?

Which of the following statement is not correct?

Flow depth and bed slope of a wide rectangular alluvial canal are 3.8 m and 1.5 × 10^–4 respectively. The velocity is found out to be 1.9 m/s. The mean size of the sediment particles is 1.6 mm. What is the ratio of rugosity coefficient given by Strickler’s formula to the actual rugosity coefficient?

What is the actual area covered (in km²) by a 20 cm × 20 cm size vertical aerial photograph, if the longitudinal overlap and side overlap are 60% and 40% respectively the scale of the photography is 1 : 20000.