91. Which one of the following minerals is softest?

(a) Calcite

(b) Apatite

(c) Orthoclase

(d) Gypsum

Answer: (d)

92. ‘Granites’ generally show three sets of joints mutually at right angles which divide the rock mass into more or less cubical blocks, such joints are called:

(a) Master joints

(b) Sheet joints

(c) Columnar joints

(d) Mural joints

Answer: (d)

93. The radius of a horizontal circular curve is 100 𝑚. The design speed is 50 kmph and design coefficient of lateral friction is 0.15. The superelevation rate required if full lateral friction is assumed to develop will be:

(a) 1 in 24.7

(b) 1 in 21.2

(c) 1 in 18.7

(d) 1 in 14.2

Answer: (b)

94. If,

𝑒 = superelevation in meters

𝑓 = coefficient of lateral friction between tyres and road surface

𝑣 = design speed for the road in meters/second

𝑅 = radius of curve in meters

The relation between super elevation, coefficient of lateral friction, the design speed and radius of curvature of the road is given by the equation:

Answer: (d)

95. The superelevation required at a horizontal curve of radius 300 𝑚, for a design speed of 80 km/ℎ𝑟 and coefficient of lateral friction of 0.15 will be nearly:

(a) 1 in 55.6

(b) 1 in 50.4

(c) 1 in 48.6

(d) 1 in 42.6

Answer: (a)

96. The natural method of ventilation for tunneling is conveniently used when:

(a) A drift is not driven from portal to portal

(b) Diameter of the tunnel is large but its length is small

(c) Tunnel is not to be laid in the direction of wind

(d) Blowing and exhausting is not done

Answer: (b)

97. Which one of the following method is adopted as temporary drainage system for tunnel?

(a) Open-ditch drainage system

(b) By providing a central drain

(c) By providing iron shed along with side drains

(d) By providing a side drain

Answer: (a)

98. Which one of the following is not an important feature of Tube Railways?

(a) The railway stations have to be of cubical form

(b) Escalators or moving stair cases are to be constructed to reach the tube railways

(c) Only electric traction is to be used to avoid the smoke and ventilation problems

(d) Automatic signaling system is to be used

Answer: (a)

99. In the design of curve for Railway track the Bernoulli’s equation for lemniscate is:

Answer: (d)

100. Which one of the following signal system in Railway signals does not fall under the classification of signals according to their functional characteristics?

(a) Stop or semaphore type of signals

(b) Hand signals

(c) Warner signals

(d) Shunting signals

Answer: (b)